Enzyme-containing particles and liquid detergent concentrate

ABSTRACT

A liquid detergent concentrate has an outer liquid detergent phase and enzyme containing particles dispersed in the liquid phase. The particles have a polymer shell formed from a condensation polymer which is permeable to water and low molecular weight components of the outer liquid phase and the core comprises the enzyme, an inner liquid detergent phase in substantially equilibrium with the outer phase and a core polymer which causes stretching as a result of osmosis when the concentrate is diluted in water. Encapsulated precipitated enzymes are also disclosed.

This invention relates to enzyme containing particles wherein the enzymecan be controllably retained within the particles despite migration ofother materials through the walls of the particles. In particular theinvention relates to liquid detergent concentrates which containparticles which contain an enzyme whereby the enzyme is protected in theconcentrate but is released when the concentrate is diluted in washwater. In particular it preferably relates to such concentrates whichcontain two enzymes wherein one would normally deactivate the other butwhich are protected from each other in the concentrate and which areavailable upon dilution in wash water.

There is extensive prior art on encapsulating active ingredients inpolymeric particles so as to attempt to protect the active ingredientfrom the environment during storage but to permit release when required.In some processes the active ingredient is distributed through apolymeric matrix. In other processes the active ingredient is present inthe core of a particle which has a polymeric shell. In some processesthere is a polymeric shell surrounding a core containing a polymericmatrix and the active ingredient.

Particular difficulties arise in those instances when it is intendedthat release of the active ingredient should occur solely as a result ofa change in the ambient environment, without any deliberate applicationof a release mechanism such as the application of external rupturingpressure. Particular problems also arise when the capsules are verysmall, for instance below 30 μm, since the capsules then have anextremely large specific surface area, ie surface area per unit mass ofparticles. Accordingly, even a very low permeation rate from the surfaceof the particles may be unacceptable with these small particles, whereasthe same permeation rate from the surface of larger particles, having amuch smaller specific surface area, may be acceptable.

It is known to be desirable to include detergent enzymes in liquiddetergent concentrates. There have been many proposals in the literatureto protect the enzyme from the continuous phase of the concentrateand/or water by providing a continuous shell and/or a matrix which isintended to protect the enzyme from the concentrate but to release itwhen the detergent concentrate is added to water to provide wash water.Examples are given in EP 356,239 and WO92/20771, and the prior artdiscussed in those. These and other known methods generally involveforming the shell by coacervation.

Although there have been proposals to include coarse particles, forinstance having a size up to 1,000 μm, in detergent concentrates, inpractice this is commercially unacceptable because the particles settleout from the concentrate. It is, instead, necessary that the particlescould be so small that they can be stably dispersed in the concentrate,and in practice this means that they should generally have a size atleast 90% by weight below 30 μm (dry size). Accordingly the particleshave a very high specific area.

Unfortunately it is very difficult to select a coacervation polymer andits conditions of use on the one hand, and a polymeric or other corecomposition on the other, so as to obtain in particles of high specificarea the optimum protection and release performance that is required. Ingeneral, either the shell is too impermeable to give effective releasewhen required or the shell permits premature relase.

A somewhat similar problem exists in systems for immobilising enzymesfor use as, for instance, catalysts in chemical (including biochemical)reactions. Either the enzyme escapes prematurely through the shell ofthe immobilising particles or the shell is so impermeable that itseverely interferes with the necessary migration through the shell ofreactants and reaction products.

A particular problem seems to arise in liquid detergents because of thetendency of the enzyme to permeate during storage through the highsurface area of the coacervate shell, if the shell is capable of givingfull release when required. This is probably due in part to the ratherlow molecular volume of the enzyme (since detergent enzymes typicallyhave a molecular weight of the order of 20,000 to 100,000) combined withthe fact that many polymer films are likely to be permeable orsemi-permeable to molecules of this size. Accordingly on prolongedstorage a significant amount of the enzyme may migrate through the largesurface area of the shell even if the permeability of the shell appearsto be low. If the shell is made sufficiently thick or cross-linked tominimise the risk of this happening it is then very difficult to achieveadequate release of the enzyme.

Various encapsulation techniques other than coacervation are known forvarious purposes and one such technique which has been used for otherprocesses is inter facial condensation (IFC) polymerisation. IFCencapsulation techniques are generally conducted in oil-in-waterdispersions (so that the oil phase becomes the core) but it is alsoknown to conduct IFC encapsulation on a water-in-oil dispersion (so thatthe water phase becomes the core).

JP-A-63-137996 describes liquid detergents containing encapsulatedmaterials wherein the encapsulation can be by coacervation or by IFCpolymerisation. It is stated that the particle size can be from 1 μm to30,000 μm but in each of the examples the particle size range is from 20μm up to 100 μm or more. Accordingly it is clear that the products whichare made by this process will have a coarser particle size, andtherefore a very much lower specific surface area, than we require.

The objective in JP 63-137996 is to include in the core a water-solubleor water absorbent polymer that will swell sufficiently when thedetergent is put into wash water to cause rupture of the capsules, withconsequential release of the core. Two of the examples show relativelycoarse capsules having a shell made by coacervation and having enzyme inthe core. They show significant loss of activity during storage but alsoshow that the residual activity is released quickly upon adding thedetergent to water.

The other example shows coarse particles of an IFC polyester polymershell wherein the core includes a high molecular weight dye (molecularweight 2 million) as the active ingredient together with anionicsurfactant and cross-linked insoluble polymer. The coarse particles aremade as a powder and are then dispersed in a shampoo. It is shown thatthere is no dye release during storage but that there is rupture andrapid release of the dye when the shampoo is added to water. The largeparticle size and the high molecular weight of dye probably contributeto the failure of the dye to permeate out of the polyester shell wallduring storage.

The fact that anionic surfactant was included in the core compositionindicates that the authors assumed that the shell would provide acomplete barrier to the permeation of anionic surfactant through theshell. Accordingly this example suggests a shell of low specific areawhich is totally impermeable (inwards or outwards) to surfactant and dyewhile in the concentrate and which ruptures on contact with water. Theshell is formed around a pre-formed particle of the cross-linkedpolymer. Because the dye has a molecular weight very much larger than adetergent enzyme, the fact that the dye did not permeate out of theselarge capsules on storage gives no useful information about how toretain and release enzyme in microcapsules having much larger surfacearea.

The use of block copolymers in IFC polymerisation is described inEP-A-671206.

We have found that it is not easily possible to achieve the desiredresult using any of the micro encapsulation procedures previouslydescribed for encapsulating detergent enzymes. In practice, either theshell wall is generally too permeable to prevent migration of therelatively low molecular weight enzyme through the high specific surfacearea provided by the shell wall or the shell wall is so impermeable andstrong that it cannot reliably release the enzyme when the concentrateis added to wash water. The processes are not capable of easyreproducible operation to give the desired combination of properties.

One object of the invention is to provide, for the first time, a liquiddetergent which includes encapsulated enzyme particles of high specificarea and which can reliably be formulated so as to achieve storagestability and rapid release. Another object is to provide improvedretention of enzyme while allowing selected permeation of materials intoor out of the particles. Another object is to provide a method ofencapsulating enzyme in such a way as to reduce unwanted or prematurerelease.

According to a first aspect of the invention we provide a liquiddetergent concentrate which, in use, is diluted with water to form washwater

and this concentrate comprises an outer liquid detergent phase andenzyme-containing particles substantially stably dispersed in the liquidphase,

and the enzyme-containing particles have a diameter at least 90% byweight below 30 μm and comprise a polymer shell surrounding a core,

wherein the polymer shell is formed of a condensation polymer and ispermeable to water and low molecular weight components of the outerliquid phase in the concentrate,

and the core comprises enzyme component, an inner liquid detergent phasein substantial equilibrium with the outer liquid phase of theconcentrate, and a core polymer which, upon dilution of the concentrateinto wash water and osmosis of water from the wash water into the core,co-operates with the water in the core to swell the particle and stretchthe shell to give a swollen particle diameter whereby the shellsubstantially prevents permeation of the enzyme during storage butpermits permeation in wash water.

The invention includes dispersions of the particles in a suitable liquidthat can be added to the liquid detergent to introduce the particlesinto the detergent concentrate.

Preferably the enzyme is in precipitated form within the core (generallydue to a precipitating monomeric electrolyte and/or polyelectrolyte inthe core). This provides additional control against premature release ofthe enzyme. This aspect of the invention extends to otherenzyme-containing capsules.

In a second aspect of the invention we provide particles which have anaqueous core comprising an enzyme surrounded by a shell (which haspreferably been formed by interfacial condensation) and the enzyme is inprecipitated form within the aqueous core and is held in precipitatedform by monomeric and/or polymeric electrolyte in the aqueous core.

The monomeric electrolyte (e.g., sodium sulphate) may be the onlyprecipitant and so the core may be free of polymeric material.Preferably however polymeric electrolyte is included to cause or improveprecipitation. This can, if desired, be the same core polymer as is usedin the first aspect of the invention to provide the osmosis effect.

The use of polyelectrolyte as part or all of the electrolyte ispreferred since it is less likely to permeate through the shellprematurely, for instance in the immobilisation of enzyme for catalysis.

The novel particles are preferably made by forming an aqueous corecomposition of enzyme and monomeric and/or polymeric precipitatingelectrolyte and thereby precipitating the enzyme in the aqueouscomposition, forming a water-in-oil dispersion of the aqueouscomposition and forming a shell around the dispersed water droplets. Theshell can be formed by coacervation but preferably it is formed byinterfacial condensation.

The particles can be large enough to be isolated as powder butpreferably 90% by weight are below 30 μm and they are present as adispersion in liquid (e.g., as a detergent concentrate). The preferredmethods of making the particles, and the materials used in the method,are described in more detail below.

As a result of the enzyme being in precipitated form, enzyme stabilityis increased and there is reduced tendency for unwanted permeationthrough the shell. This is useful in, for instance, the immobilisationof enzymes for use in chemical catalysis (e.g., in the reaction ofstarch to dextrin or dextrin to glucose). Reactants and reactionproducts can permeate the shell but the precipitated enzyme (andpolyelectraolyte if present) cannot.

It is possible to provide in the concentrates of the first aspect of theinvention, that the shell before stretching is impermeable to the enzymeto the extent that the amount of enzyme that permeates through the shellduring storage of the concentrate is very small. For instance at least80% and preferably at least 90% or 95% of the original enzyme activitywhich is provided in the particles is retained in the particles duringstorage, ie the loss during storage is less than 20% of the originalactivity.

It is also possible to provide that the stretched shell is morepermeable to the enzyme than to the core polymer and has a permeabilityto the enzyme such that substantially all the encapsulated enzymeescapes into the wash water. For instance at least 60% and preferably atleast 80% or 90% or more of the originally provided enzyme activity isreleased into the wash water. Suitable methods for determining activityare given below.

The first aspect of the invention is based in part on the fact that wehave now realised that, contrary to the general teachings relating toshell encapsulation of enzymes in liquid detergents, it is not necessaryto protect the enzyme from all the components of the liquid detergentconcentrate. Instead, we now realise that it is adequate, when usingmodern detergent enzymes, to allow enzyme to be contacted with major lowmolecular weight components in the detergent such as alkali andelectrolyte and surfactant provided that the enzyme is protected fromspecific deleterious components, such as another enzyme with which itwill interact. Accordingly we have devised an encapsulation system whichprovides capsules of high specific surface area and which, contrary tothe general thinking in the prior art, will allow permeation of lowmolecular weight components of the outer liquid phase of the detergentconcentrate into the capsule but which will prevent permeation of enzymeout of the capsule during storage (despite the capsule having a verysmall particle size) and will allow rapid release of the enzyme when theconcentrate is diluted in wash water.

The low molecular weight components that equilibrate through the shellcan be anything which has a molecular size significantly smaller thanthe encapsulated enzyme, in order that they can permeate the shell eventhough the enzyme cannot. They are usually surfactants and electrolytes,such as inorganic salts, and solvents.

We have now also realised that we can make use of outer liquidelectrolyte that has permeated into the capsule, and this is in completecontrast to the extensive prior art which is aiming at preventing themigration of liquid electrolyte from the continuous phase of thedetergent concentrate into the individual capsules. The outer liquidphase of the concentrate will usually have a high electrolyte contentand is often alkaline or highly alkaline.

In the invention, we deliberately utilise a shell which is substantiallynot permeable to the enzyme while the particle is in the concentrate butwe rely upon permeation of low molecular weight liquid components fromthe electrolyte-containing, outer continuous phase of the concentratethrough the shell into the core to such an extent that there issubstantial equilibrium between the inner liquid (in the core) and theouter liquid phase (surrounding the particle). Further, we rely uponthis inner liquid phase (due to its electrolyte content) to shrinkand/or precipitate the core polymer reversibly so that the shell is,during storage, sufficiently unstretched and strong that it issubstantially impermeable to the enzyme. When viewed by a microscope, itis sometimes possible to see the inner liquid and core polymer asdistinct phases, but substantially all the inner liquid may be absorbedinto the core polymer. The core polymer may be a solid or a gel butpreferably it remains in solution in the capsules.

Since the shell allows equilibration between the inner liquid and theouter liquid phase, it will also allow equilibration between wash water(when the concentrate is added to wash water) and the core. As a result,the concentration of inner liquid (and in particular of electrolyte) inthe core will be reduced rapidly by osmosis when the concentrate isdiluted to form wash water. This dilution of the electrolyteconcentration in the core due to the inward osmosis of water results ina significant increase in the volume of liquid in the core, and resultsin increased internal pressure and expansion of the volume occupied bythe core polymer. As a result the core expands sufficient to stretch theshell significantly. As a result of the stretching, the molecularstructure of the shell is opened out and can allow the enzyme topermeate out through the shell even though the enzyme could not permeatethrough the shell before the particle was in the wash water and theshell became stretched.

Instead of or in addition to relying on permeation through the shell,the invention also includes the possibility of the swelling of the coreand stretching of the shell being such as to cause rupture of the shell,but this generally seems to be unnecessary and preferably the release ofthe enzyme is primarily by permeation through the stretched shell.

It will be appreciated that the characteristics of the core polymer andthe shell have to be selected with respect to each other in order toobtain the desired non-release during storage and release into washwater. If the shell initially (ie in the concentrate) has very lowpermeability to enzyme, the product will have satisfactory storagestability but significant swelling will be necessary before the shell isswollen sufficiently to give adequate release of the enzyme upondilution.

Unfortunately a core polymer which co-operates with the watersufficiently to give a desirably high internal pressure and thereforeadequate stretching of a very impermeable shell will generally have atendency to swell during storage (and to stretch the shell) whileexposed to the inner liquid during storage. Accordingly if high swellingof the polymer is necessary to achieve rapid release in wash water thereis a substantial risk that some swelling and some release will occurduring storage. It is therefore necessary that the swelling capacity ofthe core polymer during storage and osmosis of water into the coreduring storage should be inadequate to stretch the shell sufficient toincrease its permeability to enzyme significantly, but that osmosis ofwater upon dilution and the swelling capacity of the polymer upondilution should be sufficient to stretch the shell from an impermeablestage to a permeable (with respect to enzyme) state.

The expansion forces which are generated internally by the core polymerand water need to be greater as the strength of the shell increases andits unstretched permeability decreases. Accordingly, if the shell isvery strong and impermeable during storage (so as to prevent permeationof enzyme during storage) then the core polymer must be capable ofgenerating stronger expansion forces than would be required if the shellis weaker, but must not cause premature stretching of the shell.

The enzyme component in the core may be provided by one or more types ofenzymes. There may be one or more types of enzymes in the outer liquidphase. Some of the particles may contain one or more enzymes and otherparticles may contain one or more other enzymes.

The first aspect of the invention is of particular value when thedetergent includes a protease enzyme and one or more other types ofenzymes, such as a lipase, cellulase, amylase or peroxidase. More detailof suitable enzymes is given below. One of the enzyme types, e.g. theprotease, is encapsulated in accordance with the invention and so thetwo types are separated from each other. Prior to the invention theinclusion in a detergent concentrate of both a protease and anon-protease was liable to result in deactivation of the non-proteasebut the encapsulation of one of the enzyme types in accordance with theinvention keeps the two types separate from one another. When theinvention provides, in the second aspect, precipitated enzymes these mayalso be detergent enzymes or they may be of any type suitable for theintended use, for instance amyloglucosidase or any other enzyme usefullyput into immobilised form by the second aspect of the invention.

The core can include material additional to the core polymer, enzyme andcomponents which have diffused from the outer liquid phase. Forinstance, it may include a second polymer (for instance a peptide) whichis to be protected from enzyme present in the outer liquid phase and/orit may contain a stabiliser for the encapsulated enzyme.

The use of a condensation polymer as the shell gives the opportunitymore easily to select a suitable combination of core polymer and polymershell than is available when using prior methods, such as coacervation.For instance it can be considered that for high specific area (ie verysmall) capsules there is a window of satisfactory performance (goodstorage and good release) between poor storage and good release on theone hand and poor release and good storage on the other. The use of acondensation polymer in accordance with the invention allows for areproducible and adequate window throughout which the process can beperformed reproducibly and efficiently as described herein, whereascoacervation tends to give a narrower and less reproducible window.

The particles are generally formed initially as a dispersion in ahydrocarbon or other water-immiscible liquid of particles having anaqueous core and this is then normally dehydrated. The core polymer,when initially converted to a solid core material, may have a largervolume than when inner liquid has permeated into the particles and sothe particles in the liquid detergent concentrate may have a sizeslightly smaller than the size to which the particles were initiallymanufactured, but the difference in size of the particles is not usuallyvery significant. Thus it is preferred for the particles to be madeinitially, in the water-immiscible liquid, to a dry size within theranges given below, and in particular at least 90% by weight below 30μm. By referring to the dry size of the particles we mean the size ofthe particles measured after the dispersion has been distilled so as toprovide a substantially anhydrous core, for instance having a totalwater content (based on the total weight of the particles) of below 20%and usually below 10% by weight. However if, in any particular process,it is not possible to dry the dispersion then the dry size can beestimated from measurement of the wet size of the particles coupled withan estimation of the extent to which the particles would shrink if theywere dried.

The size of the particles in the detergent concentrate is preferably atleast 80% (and preferably at least 90%) by weight below 15 μm or 20 μmand so the number of agglomerates having a size greater than 15 μm or 20μm should be low. Preferably the dry size is at least 70% (andpreferably 80% or 90%) by weight below 10 μm. The particles can be assmall as, for instance, 50% below 1 μm but preferably at least 50% andmost preferably at least 70% by weight and have a size in the range 1-5μm.

Another way of defining the size is that the mean particle size (on aweight average basis) is preferably below 20 μm and most preferablybelow 10 μm often in the range of 1-5 μm.

The size of the particles after the expansion of the core polymer andthe stretching of the shell must be sufficient to give the desiredrelease and generally the stretched diameter is at least 1.2 times thediameter of the initial particles and usually it is at least 1.5 or 2times the initial diameter. It is unnecessary for the diameter toincrease too much and generally it does not increase by more than 10times its initial diameter. For instance the initial mean diameter mighttypically be 5 μm and the swollen stretched mean diameter might be about12 or 15 μm. The core polymer may not occupy the full internal volume ofthe shell during storage, and the volume of the core polymer mayincrease more than the increase in volume of the particle.

The core polymer is preferably contained in a phase in the core which isseparate from the inner liquid detergent phase.

The core polymer can be any polymer which during storage of theconcentrate will cause only a moderate osmotic pressure on the shell andwill not result in premature release of enzyme but will co-operate withwater that enters by osmosis (after dilution in wash water) to cause thedesired increase in pressure and stretching, thereby releasing theenzyme. The core polymer may have a sufficiently solid characteristicthat it can be seen to expand during the inward permeation of water byosmosis.

If the core polymer is soluble in water its molecular volume and/ormolecular weight is preferably sufficiently higher than the molecularvolume and/or weight of the corresponding enzyme that the stretchedshell is more permeable to the enzyme than to the polymer, as otherwisepolymer may migrate out from the core ahead of the enzyme, in preferenceto contributing to swelling and stretching.

If the core polymer is water-soluble, it may be in solid form in thecore as a result of being precipitated out of solution in the core dueto the inner liquid, and in particular due to the generally highelectrolyte content in that. The polymer may form an insoluble complexwith the enzyme since this results in the enzyme tending to be protectedfrom the inner liquid by the solid polymer. Suitable polymers of thistype are polyvinylpyrrolidone, polyvinyl alcohol and some acrylamidepolymers (including the homopolymer).

Other polymers that can be used include water-insoluble but swellablepolymers such as cross-linked polymers of water-soluble monomers orcopolymers of soluble and insoluble monomers, for instance as describedin EP 356,239 or WO92/20771 or GB 9526668.0.

Preferably the polymer remains in solution. Suitable polymers includepolyacrylamides and some natural polymers. Preferably the core polymeris a polyelectrolyte. Such a polymer is generally formed by polymerisingethylenically unsaturated ionic monomer either alone or with non-ionicmonomer. The ionic monomer may be cationic but is generally anionic. Thepolymer may be a calcium-independent sulphonate polymer. The preferredionic monomer is acrylic acid but other ethylenically unsaturatedcarboxylic acids or sulphonic acids may be used. Polyacrylic acidhomopolymer and copolymers of acrylic acid and acrylamide or other watersoluble non-ionic monomer are very suitable. The polymer may be in freeacid form but is usually wholly or partially neutralised so that thepolymer is present as a sodium or other water soluble alkali metal salt.Preferred copolymers contain 5 to 75%, often 10 to 50%, by weight sodiumacrylate or other acrylic acid salt with the balance being acrylamide.The molecular weight is generally below 2 million, for instance in therange 50,000 to 400,000, often in the range 100,000 to 200,000 (measuredby gel permeation chromatography).

The polymer shell can be formed of any suitable condensation polymercapable of being formed by a convenient condensation polymerisationreaction between appropriate condensation reactants. Preferably one issubstantially oil soluble and water insoluble and the other issubstantially water soluble. The reactants are chosen so as to give thedesired condensate polymer. It is particularly preferred for thecondensate to be a polyamide but other condensates which can be formedin the invention are polyesters, polyurethanes, polyureas and epoxies.The use of polyamide is particularly useful in the invention since itfacilitates control of the manufacture to within the window that givesgood storage and good release.

When the condensate is a polyamide, it is best obtained by reaction of adiamine (or higher amine) with a dicarboxylic acid (or higher carboxylicacid), usually as a derivative such as an acid halide or anhydride. Theamine is preferably substantially water-soluble (when in free base form)and can be a material such as ethylene diamine, hexamethylene diamine,hexane diamine, diethylene tetramine, ethylene tetramine, diaminobenzene, piperazine, tetramethylene pentamine or, preferably, diethylenetriamine (DETA).

The acid component is preferably the oil soluble and can be in the formof an acid halide. It can be, for instance, adipyl, sebacyl or phthalylchloride or dodecanedioc acid chloride but is preferably terephthaloylchloride.

When the condensate polymer is a polyester it can be formed by reactionbetween, for instance, any of the acids or acid derivatives mentionedabove as oil soluble reactant together with a water-soluble polyol suchas ethylene glycol, butane diol, polycaprolactone diol or Bisphenol A.

When the condensate polymer is a polyurethane it can be formed byreaction between a suitable hydroxy or amine compound selected from anythose discussed above as the water-soluble reactant and an oil solubleisocyanate reactant such as toluene di-isocyanate or other suitablematerial such a hexamethylenebis chloroformate.

Another type of polyurethane can be obtained by using an oil-solubleoligomeric isocyanate. This reacts with water at the interface to formamino groups which react with other isocyanate groups in the oil phaseto form film at the interface.

When the condensate polymer is an epoxy, it can be made by reactionbetween, for instance, ethylene diamine or other water-soluble amine orhydroxy compound with an epoxy resin as oil soluble reactant.

The shell is best formed by interfacial condensation (IFC)polymerisation around particles which are to provide the core. In apreferred way of conducting the IFC polymerisation we form an emulsionof an aqueous composition comprising core material and water-soluble IPCreactant (which can be water) in a water-immiscible liquid, we includean oil- soluble IFC reactant in the water-immiscible liquid and we allowreaction to occur between the reactants, thereby forming particles ofcore material encapsulated within an IPC polymer shell.

The formation of the IFC shell, and the stability of the final product,can be improved by conducting the polymerisation in the presence of anoil-soluble or oil-swellable polymeric stabiliser.

When carrying out the initial manufacture of the particles having anaqueous core, an aqueous composition which is to provide the corematerial is dispersed into a water-immiscible non-aqueous liquid and awater-soluble IFC reactant is included. Generally the reactant is mixedinto the aqueous core composition before that is dispersed in thewater-immiscible liquid, but if desired it can be mixed into apre-formed dispersion of the aqueous composition in the water-immiscibleliquid. The oil-soluble polymeric stabiliser is preferably included inthe oil phase before IFC polymerisation occurs and in practice it isusually preferred for the stabiliser to be added to the water-immiscibleliquid before dispersing the aqueous core composition into it, althoughif desired some or all of the stabiliser can be added with or after theaqueous core composition.

If the oil-soluble IFC reactant is substantially unreactive under theconditions prevailing during the formation of the initial dispersionthen the reactant can also be included in the water-immiscible liquidbefore or during the formation of the dispersion of aqueous corecomposition in the water-immiscible liquid. Often, however, it ispreferred to form the aqueous dispersion of aqueous core composition andwater-soluble IFC reactant in water-immiscible liquid which contains theamphipathic polymeric stabiliser and then mix the oil-soluble IFCreactant into the dispersion.

The formation of the dispersion will be conducted with whatever level ofhomogenisation is required in order to achieve the desired particlesize. Usually one or more passes through a Silverson or otherhomogeniser may be required.

Reaction between the water-soluble and oil-soluble IFC reactants is thenallowed to occur. Depending upon the combination of reactants, this mayoccur relatively spontaneously at the mixing temperature or, moreusually, reaction is promoted by warming the entire dispersion, forinstance to a temperature in the range of 30° C.-90° C. Alternatively itcan be desirable to warm the dispersion to a suitable reactiontemperature prior to adding the oil soluble reactant or to warm thereactant (often dissolved in solvent) prior to addition to thedispersion. The reactant can be added in neat form but in order tofacilitate mixing of the oil soluble reactant into the preformeddispersion, the reactant is preferably added as a solution in an organicsolvent. The solvent becomes part of the water-immiscible liquid phaseof the reaction.

It is generally desirable to stir the dispersion while the reactionoccurs. Although the reaction may appear to be substantially completequite quickly, for instance within five minutes from adding theoil-soluble IFC reactant, it is generally desirable to continue thestirring at the chosen reaction temperature for at least ten minutes upto an hour or more, typically around half an hour, to give maximumopportunity for full reaction to occur. Stirring may then bediscontinued and the resultant composition either used as such or, moreusually, subjected to dehydration and, preferably, solvent exchange bythe general methods described above.

By referring to a water-soluble IFC reactant we mean a reactant whichdissolves in the aqueous core composition (or water when this is thereactant). By referring to an oil-soluble IFC reactant and oil-solublepolymeric stabiliser we mean a reactant or stabiliser which dissolves inthe water-immiscible liquid. Accordingly the water-soluble IFC reactantwill partition into the aqueous phase and the oil-soluble IFC reactantand the polymeric stabiliser will partition into the water-immiscibleliquid with a significant partition co-efficient, usually at least 5 andgenerally above 10. The amphipathic stabiliser need not be truly solublein the water-immiscible liquid (provided it is much less soluble inwater) but may instead be in the form of a colloidal or other dispersionand so maybe regarded as oil-swellable.

The water-immiscible liquid can consist of a single non-aqueous liquidor can be a blend of two or more non-aqueous liquids. It should bewater-immiscible so as to minimise migration of the aqueous corecomposition and the water-soluble IFC reactant into the oil phase. Itmay be any environmentally acceptable water-immiscible liquid which hasconvenient volatility and other properties for the formation of thedispersion and for its eventual removal by distillation (ifappropriate). Preferably it is a hydrocarbon, preferably a relativelylow boiling and therefore volatile, aliphatic hydrocarbon. It isnormally a paraffinic hydrocarbon. It is preferably substantially freeof environmentally undesirable materials such as chlorocarbons.

The polymeric stabiliser is preferably amphipathic, by which we meanthat it includes recurring hydrophilic and hydrophobic monomer units.

Some degree of useful stabilisation can be achieved using non-ionicblock co-polymers such as ethylene oxide-propylene oxide condensates andcondensates of polyethylene glycol with hydroxy stearic acid or as in EP671206. However it appears that the best overall results (having regardsto stability in the initial emulsion, stability in the final product,and shell characteristics) are obtained when the stabiliser is a randomcopolymer of at least one ionic ethylenically unsaturated monomer withat least one non-ionic water-insoluble ethylenically unsaturatedmonomer, i.e., a polymer formed by polymerising the monomers in thepresence of each other.

Accordingly, the amphipathic polymeric stabiliser is preferably ionic.It can be amphoteric or cationic but preferably is anionic and thus ispreferably a co-polymer of at least one anionic monomer with at leastone water-insoluble non-ionic monomer. The molar amount of the ionicmonomer is generally in the range 1 to 50% (often 10 to 30%) based onthe total molar amount of ionic and water-insoluble non-ionic monomers.

In general suitable stabilisers are addition copolymers containing bothhydrophobic and hydrophilic moieties in such a ratio as to reside at theinterface between the oil and water phase.

The water-insoluble non-ionic monomers should have a partitioncoefficient K between hexane and deionised water at 20° C. of at least 5and preferably at least 10. Suitable hydrophobic monomers include higheralkyl esters of α, β-ethylenically unsaturated carboxylic acids such asdodecyl acrylate, dodecyl methacrylate, tridecyl acrylate, tridecylmethacrylate, tetradecyl methacrylate, octadecyl acrylate, Octadecylmethacrylate, ethyl half esters of maleic anhydride, diethyl maleate,and other alkyl esters derived from the reaction of alkanol having 4 to20, preferably 8 to 20, carbon atoms, with ethylenically unsaturatedcarboxylic acid such as acrylic acid, methacrylic acid, fumaric acid,itaconic acid and acconitic acid. Other suitable hydrophobic monomersinclude styrene, alkyl styrenes such as methyl styrene, vinyl estersincluding vinyl acetate, vinyl halides, acrylonitrile,methacrylonitrile, ethylene, butylene, butadiene and other olefines andallyl ethers of non-ionic ethoxylated surfactants.

Suitable hydrophilic moieties include all water-soluble ethylenicallyunsaturated monomers that undergo addition polymerisation, such asacrylic acid, methacrylic acid, acrylamide, 2-acrylamide-2-methylpropane sulphonic acid, itaconic acid, maleic acid, fumaric acid;ethylenically unsaturated quaternary compounds such as dimethyl aminoethyl acrylate or methacrylate quaternised with methyl chloride, diallyldimethyl ammonium chloride vinyl or allyl sulphonates, vinyl or allylamines, hydroxy lower-alkyl esters of ethylenically unsaturated acids,and other alkylaminoalkyl—(meth) acrylates and—(meth) acrylamides.

It is particularly desirable to use a polycarboxylic acid, especially adi-carboxylic acid such as maleic acid (utilised either as the acid orthe anhydride) or itaconic acid as part or all of the acid component(for distance at least 20% by weight of the acid, often at least 50%).

Other ethylenically unsaturated monomers may also be included, so as tomodify the solubility parameters of the stabilisers to promoteprecipitation and residence at the interface between the oil and waterphase.

Suitable monomers are short chain alkyl esters of ethylenicallyunsaturated carboxylic acids such as acrylic acid, methacrylic acid,fumaric acid, itaconic acid and aconitic acid, where the alkyl groupgenerally contains between 1 and 4 carbon atoms e.g. methyl acrylate ormethacrylate, butyl acrylate or methacrylate.

Ratios of hydrophobic to hydrophilic monomer can be between 90 parts byweight of hydrophobic monomer and 10 parts by weight of hydrophilicmonomer to 20 parts by weight of hydrophobic monomer and 80 parts byweight of hydrophilic monomer.

When the short chain esters are incorporated they replace thehydrophobic monomer in the copolymer, and the dry weight ratio of shortchain ester will not exceed 50 parts. Minor amounts of othernon-interfering monomers can be included such as difunctional or otherpolyfunctional monomers.

The optimum monomer blend, and thus the optimum stabiliser in anyparticular process, will depend inter alia on the choice ofwater-immiscible liquid and the core material and the IFC reactants andthe proportions of each of these.

The stabiliser usually has a molecular weight (measured by gelpermeation chromatography, of above 2000 and preferably above 10,000 upto, for instance, 100,000 or 200,000.

The selection of a suitable blend can be done by performing the IFCpolymerisation in a water-in-oil emulsion and subjecting the product tomicroscopic examination. Additionally a simple test to facilitateselection of suitable aqueous and oil phases is as follows.

The aqueous phase containing the water-soluble IFC reactant is spread asa layer in a vessel. The oil phase is spread over it with minimumintermixing at the chosen reaction temperature, the oil phase containingthe chosen amount of IFC reactant. It will be found that the quality ofthe film which is formed at the interface varies according to thecontent of the two phases, for instance any stabiliser and its amount.Once a combination has been found that gives both a satisfactorywater-in-oil dispersion and a film in the test described above, it ispredictable that reasonable wall formation will occur. Optimum resultscan be selected by varying concentrations and materials and observingperformance. Accordingly once a monomer concentration and stabiliserconcentration has been found which gives a reasonable film, thestabiliser and its amount can be varied in successive tests and theeffect on film quality observed.

When the stabiliser is replaced by, or supplemented by a significantamount of, a conventional non-polymeric water-in-oil emulsifier thenfilm quality may deteriorate significantly and a coherent film may notbe obtained. The reason for this is not clear but it seems that theemulsifier may promote emulsification of the phases and promoteprecipitation polymerisation within the oil phase due to hydrophilicmicelle formation within the oil phase, whereas the stabiliser maypromote emulsification of the phases and concentration of thepolymerisation at the interface.

As described in the International application No. PCT/GB96/03231(WO-A-9724197) filed even date herewith claiming priority from GB9526707.6 (the entire disclosure of which is herein incorporated byreference) it is preferred that the polymer shell should comprise anassociation product of (a) the IFC condensation product formed byreaction between a first IFC reactant having at least two firstcondensation groups and a second IFC reactant having at least two secondcondensation groups and (b) the amphipathic polymeric stabiliser,wherein the stabiliser will concentrate at the interface between oil andwater and has recurring hydrophobic groups and recurring reactivehydrophilic groups which associate with the second condensation groups.Preferably the stabiliser comprises carboxylic groups, preferably beinga copolymer of monomers comprising ethylenically unsaturateddicarboxylic acid, and the second reactant is an amine. The preferredstabiliser is a copolymer of styrene and/or alkyl (meth) acrylate ashydrophobic monomer and ethylenically unsaturated polycarboxylic acid(such as maleic anhydride), and the second reactant is diethylenetriamine or other free base amine which is water soluble but also hassome solubility in oil.

Generally the dispersion of aqueous core composition and second IFCreactant is formed and is then blended with the first IFC reactant.Generally the dispersion is homogenised, for instance for at least threeminutes, before blending with the first IFC reactant so as to allow forassociation to occur between reactive hydrophilic groups on thestabiliser and the second condensation groups of the second IFC reactant(e.g., association between carboxylic groups and amine groups). Theassociation may comprise an ionic association or a condensationreaction. Preferably the water in oil dispersion is homogenised for atleast three minutes and often five to twenty minutes or more beforeblending with the first IFC reactant. The blending is best conducted bymixing the dispersion and the first reactant under conditions whereinthe weight ratio of dispersion to first reactant remains substantiallyconstant through the blending process, for instance by in-line blendingof a feed containing the dispersion and a feed containing the firstreactant.

The condensation polymerisation is preferably conducted in thesubstantial absence (e.g., below 3%, preferably below 1% and preferablyzero or near zero) of non-polymeric water-in-oil emulsifier or any othermaterial which would interfere with satisfactory performance of theprocess.

The use of the polymeric stabiliser facilitates the production of moreuniform particles and in particular it facilitates the production of asubstantially stable dispersion. It can beneficially influence theproduction of the IFC shell. For instance the amount of either or boththe reactants required to obtain a shell of defined properties can bereduced by optimising the stabiliser and its amount. Further theparticles made using the stabiliser can be dispersed stably into anotherliquid (for instance the liquid detergent concentrate) more easily thanif the polymeric stabiliser is not used.

The process generally comprises the subsequent step of distilling offmost or all of the water from the aqueous core composition until theparticles comprise a substantially anhydrous core encapsulated withinthe IFC polymer shell. The distillation is often referred to asazeotropic distillation as some of the organic liquid is usuallydistilled off with the water.

The particles are generally made initially as a water-in-oil dispersion(emulsion) in a water-immiscible liquid, generally a hydrocarbon. Theresultant dispersion, optionally after distillation to render the coresubstantially anhydrous, can be supplied to the user as such, forinstance for incorporation into a detergent concentrate. Often, however,it is preferred to exchange the water-immiscible liquid in which thedispersion is formed for a different organic liquid which can be asurfactant or a water-miscible liquid and can contain some water.However it is generally convenient for the amount of water in thisliquid to be kept relatively low, for instance below 20% weight and sothe final composition will be a dispersion in a substantiallynon-aqueous liquid.

A suitable method of achieving this change in the liquid is by a methodsuch as is described in WO 94/25560. The method comprises forming theinitial IFC dispersion in water-immiscible liquid, optionallydehydrating the dispersed particles by azeotropic distillation of thedispersion and adding to the dispersion liquid selected from surfactantsand water-miscible liquids and water-immiscible liquids which is lessvolatile than the initial water-immiscible liquid, and distilling theinitial water-immiscible liquid off from the dispersion until the amountthereof remaining in the dispersion is below 20% by weight of the liquidphase in the dispersion.

Although the dispersion is often dehydrated (before, during or afteradding the surfactant or other liquid), removal of water is notessential since the water may often satisfactorily equilibrate with thecontinuous phase. This discovery is useful in the present invention butis also applicable to processes of the type described in WO 94/25560.

The added liquid may be water miscible and organic and may be aqueous.It may be a glycol but is usually a non-ionic or other surfactant, withthe result that the final product is a dispersion of the particles inthe surfactant. Thus the product may be a dispersion of aqueousparticles in an aqueous liquid. The amount of particles in thedispersion may be above 5% or 10% dry weight, often above 20% or more.The dispersion may be fluid or meltable, i.e. the non-aqueous liquid maybe a wax when cool and may have to be heated in order to provide aliquid state. Reference should be made to WO94/25560 for a fulldescription of suitable materials and process conditions. When theinvention is applied to liquid detergents, the enzyme should be adeteregent enzyme. When the invention is directed to the precipitationaspect, other enzymes can be incorporated according to their intendeduse.

An enzyme may be introduced, for example, in the form of a purifiedenzyme or an extract (such as a fermentation broth) containign celldebris and/or other by-products from the initial production of theenzyme. Very suitable enzymes include enzymes of types which may beusefully included in a deteregent, as well as enzymes of types employedin industrial processes (e.g., in the starch-processing industry, intextile treatment or in the protein industry).

Enzymes of relevance in the context of the present invention include,but are by no means limited to, the following [enzyme classificationnumbers (EC numbers) referred to herein being in accordance with theRecommendations (1992) of the Nomenclature Committee of theInternational Union of Biochemistry and Molecular Biology, AcademicPress Inc., 1992].

Proteases (i.e., peptidases, EC 3.4), such as proteases obtainable fromanimals, plants or—in particular—microorganisms (notably bacterial orfungi), as well as mutants of such proteases produced by chemicalmodification or genetic engineering. Suitable commercially availableproteases include Alcalase™, Savinase™, Everlase™, Durazym™, Esperase™and Flavourzyme™ (all available from Novo Nordisk A/S, Denmark)Maxatase™, Maxacal™, Maxapem™ and Properase™ (available fromGist-Brocades), Purafect™ and Purafect™ OXP (available from GenencorInternational), as well as Opticlean™ and Optimase™ (available fromSolvay Enzymes).

Lipases (e.g., triacylglycerol lipases, EC 3.1.1.3), such as lipasesobtainable from animals (e.g., mammals), plants or—inparticular—microorganisms (notably bacteria or fungi), as well asmutants of such lipases produced by chemical modification or geneticengineering. Lipases of types referred to in the literature as“cutinases” (such those obtainable from Pseudomonas mendocina asdescribed in WO88/09367, or from Fusarium solani f. pisi as described,e.g., in WO90/09446) are included in this connection. Suitablecommercially available lipases include Lipolase™ and Lipolase Ultra™(available from Novo Nordisk A/S, Denmark), Lipomax™, Lumafast™ and M1Lipase™ (available from Genencor International), and Lipase P “Amano”(available from Amano Pharmaceutical Co. Ltd.).

Amylases [e.g., α-amylases, EC 3.2.1.1, β-amylases, EC 3.2.1.2, andamyloglucosidases (glucoamylases), EC 3.2.1.3], such as amylasesobtainable from microorganisms (notably bacteria or fungi), as well asmutants of such amylases produced by chemical modification or geneticengineering. Suitable commercially available amylases include Termamyl™,BAN™, Duramyl™, Fungamyl™ and AMG™ (all available from Novo Nordisk A/S,Denmark), as well as Rapidase™ and Maxamyl™ P (available from GenencorInternational).

Cellulases (e.g., endo-1,4-β-glucanases, EC 3.2.1.4), such as cellulasesobtainable from microorganisms (notably bacteria or fungi), as well asmutants of such cellulases produced by chemical modification or geneticengineering. Suitable commercially available cellulases includeCelluzyme™, Celluclast™, Cellusoft™ and Denimax™ (all available fromNovo Nordisk A/S, Denmark), and KAC-500(B)™ (available from KaoCorporation).

Oxidoreductases [EC 1; including phenol-oxidases such as laccases (EC1.10.3.2) and other enzymes classified under EC 1.10.3; and peroxidases(EC 1.11.1), notably those classified under EC 1.11.1.7], such asoxidoreductases obtainable from plants or microorganisms (notablybacteria or fungi), as well as mutants of such oxidoreductases producedby chemical modification or genetic engineering. Suitable laccasesinclude those obtainable from fungal species within genera such asAspergillus, Neurospora, Podospora, Botrytis, Collybia, Fomes, Lentinus,Pleurotus, Trametes, Polyporus, Rhizoctonia, Coprinus, Psatyrella,Myceliophthora, Schytalidium, Phlebia, Coriolus, Pyricularia orRigidoporus, such as laccase obtainable from Trametes villosa (alsopreviously known, inter alia, as Polyporus pinsitus) or fromMyceliophthora thermophila. Suitable peroxidases include plant-derivedperoxidases, such as horseradish peroxidase or soy bean peroxidase, aswell as peroxidases obtainable from fungal species within genera such asFusarium, Humicola, Trichoderma, Myrothecium, Verticillium, Arthromyces,Caldariomyces, Ulocladium, Embellizopus or Mucor, or from bacterialspecies within genera such as Streptomyces, Streptoverticillium,Bacillus, Rhodobacter, Rhodomonas, Streptococcus, Pseudomonas orMyxococcus. Other sources of potentially useful peroxidases are listedin B. C. Saunders et al, Peroxidase, London 1964, pp. 41-43.Particularly useful peroxidases include those obtainable from Coprinusspecies such as C. cinereus or C. macrorhizus (as described, e.g., inWO92/16634).

Other relevant types of enzymes within the context of the inventioninclude xylose isomerases (EC 5.3.1.5) useful, e.g., in the conversionof D-glucose to D-fructose (e.g., in the manufacture of fructose syrupsin the starch-processing industry).

As mentioned above, a stabiliser for the enzyme may be included in thecore.

Preferably the enzyme is in precipitated form in the shell, theprecipitation preferably being caused by electrolyte. The precipitationcan be brought about by permeation of electrolyte through the shellafter the formation of the particles, but preferably the enzyme isprecipitated before the shell is formed around the core composition.Thus preferably the aqueous core composition comprises electrolyte whichcauses precipitation of the enzyme. The electrolyte preferably comprisespolyelectrolyte, such as any of the polyelectrolytes discussed above,since the polyelectrolyte cannot permeate out through the shell duringstorage. Generally the aqueous core composition comprises monomericelectrolyte, such as sodium sulphate or any other electrolyte known tobe capable of precipitating an enzyme. Best results are generallyobtained when the aqueous core composition, before encapsulation in theshell, contains both polyelectrolyte and monomeric electrolyte. Examplesof other monomeric electrolytes which can be used include alkali metalcarbonates, bicarbonates, acetates, carboxylates and phosphates.

It should be noted that the sodium chloride-polymer system used inExample 1 of JP-A-63-137996 does not result in precipitation of theenzyme but, instead, merely encapsulates a solution of the enzyme.

The proportions of the IFC reactants, and the total weight of thepolymer shell, can be selected according to the desired properties ofthe shell. Generally the shell provides from 2%-50%, often around10%-30%, by weight of the total dry weight of the encapsulated material(i.e. shell and dehydrated core). The molar proportions of thewater-soluble and oil soluble IFC reactants are generally in the range10:1 to 1:10. For instance the molar ratio water-soluble reactantoil-soluble reactant may be 10:1 to 1:3 often 5:1 to 1:1.

The amount of polymeric stabiliser is generally in the range 0.1% to 10%usually around 0.5%-3%, by weight stabiliser based on the total weightof the dispersion in which the particles are formed. The amount based onthe dry weight of the particles is generally in the range 0.5 to 30%often around 3%-10% by weight. The amount of aqueous core compositionand water-soluble IFC reactant is usually at least 5 or 10% by weight,preferably at least 25%, but is usually not more than 60 or 70%, byweight of the aqueous dispersion.

The dry weight of the (core) in the aqueous dispersion is usually atleast 2% or 5% by weight and often at least 10%. Often it is not morethan 40 or 50% by weight. The amount of polymeric shell is often atleast 5 or 10%, based on the total dry weight of the core plus shell,often not more than 50 or 60%.

The dispersion of enzyme particles in hydrocarbon, surfactant or otherliquid can be blended into the chosen detergent concentrate.

The detergent concentrate can be any liquid detergent concentrate whichhas an electrolyte-containing liquid phase that can permeate through theshell to provide inner liquid having electrolyte content sufficient tocause the core polymer to be shrunken whereby it can swell whensufficient water permeates through the shell by osmosis.

As indicated above, the concentrate may contain one or more types ofenzyme in particles and one or more other types of enzyme in liquidphase. If desired, different enzymes may be separately encapsulated intodifferent particles, and the resulting sets of particles may be blendedinto the liquid detergent.

The amount of dilution of the liquid detergent to form the wash waterdepends upon the composition of the detergent and will be conventional.

The invention includes not only the detergent concentrates but alsodispersions of the particles which can be added to a liquid detergentconcentrate to form a concentrate according to the invention.

The concentrate may comprise a surfactant system, wherein the surfactantcan be nonionic and/or anionic and/or cationic and/or ampholytic and/orzwitterionic and/or semi-polar. The concentrate may be for laundry ordish uses.

The detergent may be aqueous, typically up to 70% water and 0-30%organic solvent, or non-aqueous. The amount of surfactant may be 0.1 to60% by weight.

The surfactant is typically present at a level from 0.1% to 60% byweight.

The surfactant is preferably formulated to be compatible with the enzymecomponents present in the composition. In liquid or gel compositions thesurfactant is most preferably formulated in such a way that it promotes,or at least does not degrade, the stability of any enzyme in thesecompositions.

Preferred systems to be used according to the present invention compriseas a surfactant one or more of the nonionic and/or anionic surfactantsdescribed herein.

Polyethylene, polypropylene, and polybutylene oxide conden-sates ofalkyl phenols are suitable for use as the nonionic surfactant of thesurfactant systems of the present invention, with the polyethylene oxidecondensates being preferred. These compounds include the condensationproducts of alkyl phenols having an alkyl group containing from about 6to about 14 carbon atoms, preferably from about 8 to about 14 carbonatoms, in either a straight chain or branched-chain configuration withthe alkylene oxide. In a preferred embodiment, the ethylene oxide ispresent in an amount equal to from about 2 to about 25 moles, morepreferably from about 3 to about 15 moles, of ethylene oxide per mole ofalkyl phenol. Commercially available nonionic surfactants of this typeinclude Igepal™ CO-630, marketed by the CAF Corporation; and Triton™X-45, X-114, X-100 and X-102, all marketed by the Rohm & Haas Company.These surfactants are commonly referred to as alkylphenol alkoxylates(e.g., alkyl phenol ethoxylates).

The condensation products of primary and secondary aliphatic alcoholswith about 1 to about 25 moles of ethylene oxide are suitable for use asthe nonionic surfactant of the nonionic surfactant systems of thepresent invention. The alkyl chain of the aliphatic alcohol can eitherbe straight or branched, primary or secondary, and generally containsfrom about 8 to about 22 carbon atoms. Preferred are the condensationproducts of alcohols having an alkyl group containing from about 8 toabout 20 carbon atoms, more preferably from about 10 to about 18 carbonatoms, with from about 2 to about 10 moles of ethylene oxide per mole ofalcohol. About 2 to about 7 moles of ethylene oxide and most preferablyfrom 2 to 5 moles of ethylene oxide per mole of alcohol are present insaid condensation products. Examples of commercially available nonionicsurfactants of this type include Tergitol™ 15-S-9 (The condensationproduct of C₁₁-C₁₅ linear alcohol with 9 moles ethylene oxide),Tergitol™ 24-L-6 NMW (the condensation product of C₁₂-C₁₄ primaryalcohol with 6 moles ethylene oxide with a narrow molecular weightdistribution), both marketed by Union Carbide Corporation; Neodol™ 45-9(the condensation product of C₁₄-C₁₅ linear alcohol with 9 moles ofethylene oxide), Neodol™ 23-3 (the condensation product of C₁₂-C₁₃linear alcohol with 3.0 moles of ethylene oxide), Neodol™ 45-7 (thecondensation product of C₁₄-C₁₅ linear alcohol with 7 moles of ethyleneoxide), Neodol™ 45-5 (the condensation product of C₁₄-C₁₅ linear alcoholwith 5 moles of ethylene oxide) marketed by Shell Chemical Company,Kyro™ EOB (the condensation product of C₁₃-C₁₅ alcohol with 9 molesethylene oxide), marketed by The Procter & Gamble Company, and GenapolLA 050 (the condensation product of C₁₂-C₁₄ alcohol with 5 moles ofethylene oxide) marketed by Hoechst. Preferred range of HLB in theseproducts is from 8-11 and most preferred from 8-10.

Also useful as the nonionic surfactant of the surfactant systems of thepresent invention are alkylpolysaccharides disclosed in U.S. Pat. No.4,565,647, having a hydrophobic group containing from about 6 to about30 carbon atoms, preferably from about 10 to about 16 carbon atoms and apolysaccharide, e.g. a polyglycoside, hydrophilic group containing fromabout 1.3 to about 10, preferably from about 1.3 to about 3, mostpreferably from about 1.3 to about 2.7 saccharide units. Any reducingsaccharide containing 5 or 6 carbon atoms can be used, e.g., glucose,galactose and galactosyl moieties can be substituted for the glucosylmoieties (optionally the hydrophobic group is attached at the 2-, 3-,4-, etc. positions thus giving a glucose or galactose as opposed to aglucoside or galactoside). The intersaccharide bonds can be, e.g.,between the one position of the additional saccharide units and the 2-,3-, 4-, and/or 6- positions on the preceding saccharide units.

The preferred alkylpolyglycosides have the formula

R²O(C_(n)H_(2n)O)_(t)(glycosyl)_(x)

wherein R² is selected from the group consisting of alkyl, alkylphenyl,hydroxyalkyl, hydroxyalkylphenyl, and mixtures thereof in which thealkyl groups contain from about 10 to about 18, preferably from about 12to about 14, carbon atoms; n is 2 or 3, preferably 2; t is from 0 toabout 10, pre-ferably 0; and x is from about 1.3 to about 10, preferablyfrom about 1.3 to about 3, most preferably from about 1.3 to about 2.7.The glycosyl is preferably derived from glucose. To prepare thesecompounds, the alcohol or alkylpolyethoxy alcohol is formed first andthen reacted with glucose, or a source of glucose, to form the glucoside(attachment at the 1-position). The additional glycosyl units can thenbe attached between their 1-position and the preceding glycosyl units2-, 3-, 4-, and/or 6-position, preferably predominantly the 2-position.

The condensation products of ethylene oxide with a hydrophobic baseformed by the condensation of propylene oxide with propylene glycol arealso suitable for use as the additional nonionic surfactant systems ofthe present invention. The hydrophobic portion of these compounds willpreferably have a molecular weight from about 1500 to about 1800 andwill exhibit water insolubility. The addition of polyoxyethylenemoieties to this hydrophobic portion tends to increase the watersolubility of the molecule as a whole, and the liquid character of theproduct is retained up to the point where the polyoxyethylene content isabout 50% of the total weight of the condensation product, whichcorresponds to condensation with up to about 40 moles of ethylene oxide.Examples of compounds of this type include certain of the commerciallyavailable Pluronic™ surfactants, marketed by BASF.

Also suitable for use as the nonionic surfactant of the nonionicsurfactant system of the present invention, are the condensationproducts of ethylene oxide with the product resulting from the reactionof propylene oxide and ethylenediamine. The hydrophobic moiety of theseproducts consists of the reaction product of ethylenediamine and excesspropylene oxide, and generally has a molecular weight of from about 2500to about 3000. This hydrophobic moiety is condensed with ethylene oxideto the extent that the condensation product contains from about 40% toabout 80% by weight of polyoxyethylene and has a molecular weight offrom about 5000 to about 11000. Examples of this type of nonionicsurfactant include certain of the commercially available Tetronic™compounds, marketed by BASF.

Preferred for use as the nonionic surfactant of the surfactant systemsof the present invention are polyethylene oxide condensates of alkylphenols, condensation products of primary and secondary aliphaticalcohols with from about 1 to about 25 moles of ethyleneoxide,alkylpolysaccharides, and mixtures hereof. Most preferred are C₈-C₁₄alkyl phenol ethoxylates having from 3 to 15 ethoxy groups and C₈-C₁₈alcohol ethoxylates (preferably C₁₀ avg.) having from 2 to 10 ethoxygroups, and mixtures thereof.

Highly preferred nonionic surfactants are polyhydroxy fatty acid amidesurfactants of the formula

wherein R¹ is H, or R₁ is C₁₋₄ hydrocarbyl, 2-hydroxyethyl,2-hydroxypropyl or a mixture thereof, R² is C₅₋₃₁ hydrocarbyl, and Z isa polyhydroxyhydrocarbyl having a linear hydrocarbyl chain with at least3 hydroxyls directly connected to the chain, or an alkoxylatedderivative thereof. Preferably, R¹ is methyl, R² is straight C₁₁₋₁₅alkyl or C₁₆₋₁₈ alkyl or alkenyl chain such as coconut alkyl or mixturesthereof, and Z is derived from a reducing sugar such as glucose,fructose, maltose or lactose, in a reductive amination reaction.

Highly preferred anionic surfactants include alkyl alkoxylated sulfatesurfactants. Examples hereof are water soluble salts or acids of theformula RO(A)_(m)SO₃M wherein R is an unsubstituted C₁₀-C-₂₄ alkyl orhydroxyalkyl group having a C₁₀-C₂₄ alkyl component, preferably aC₁₂-C₂₀ alkyl or hydro-xyalkyl, more preferably C₁₂-C₁₈ alkyl orhydroxyalkyl, A is an ethoxy or propoxy unit, m is greater than zero,typically between about 0.5 and about 6, more preferably between about0.5 and about 3, and M is H or a cation which can be, for example, ametal cation (e.g., sodium, potassium, lithium, calcium, magnesium,etc.), ammonium or substituted-ammonium cation. Alkyl ethoxylatedsulfates as well as alkyl propoxylated sulfates are contemplated herein.Specific examples of substituted ammonium cations include methyl-,dimethyl, trimethyl-ammonium cations and quaternary ammonium cationssuch as tetramethyl-ammonium and dimethyl piperdinium cations and thosederived from alkylamines such as ethylamine, diethylamine,triethylamine, mixtures thereof, and the like. Exemplary surfactants areC₁₂-C₁₈ alkyl polyethoxylate (1.0) sulfate (C₁₂-C₁₈E(1.0)M), C₁₂-C₁₈alkyl polyethoxylate (2.25) sulfate (C₁₂-C₁₈(2.25)M, and C₁₂-C₁₈ alkylpolyethoxylate (3.0) sulfate (C₁₂-C₁₈E(3.0)M), and C₁₂-C₁₈ alkylpolyethoxylate (4.0) sulfate (C₁₂-C ₁₈E(4.0)M), wherein M isconveniently selected from sodium and potassium.

Suitable anionic surfactants to be used are alkyl ester sulfonatesurfactants including linear esters of C₈-C₂₀ carboxylic acids (i.e.,fatty acids) which are sulfonated with gaseous SO₃ according to “TheJournal of the American Oil Chemists Society”, 52 (1975), pp. 323-329.Suitable starting materials would include natural fatty substances asderived from tallow, palm oil, etc.

The preferred alkyl ester sulfonate surfactant, especially for laundryapplications, comprise alkyl ester sulfonate surfactants of thestructural formula:

wherein R³ is a C₈-C₂₀ hydrocarbyl, preferably an alkyl, or combinationthereof, R⁴ is a C₁-C₆ hydrocarbyl, preferably an alkyl, or combinationthereof, and M is a cation which forms a water soluble salt with thealkyl ester sulfonate. Suitable salt-forming cations include metals suchas sodium, potassium, and lithium, and substituted or unsubstitutedammonium cations, such as monoethanolamine, diethonolamine, andtriethanolamine. Preferably, R³ is C₁₀-C₁₆ alkyl, and R⁴ is methyl,ethyl or isopropyl. Especially preferred are the methyl ester sulfonateswherein R³ is C₁₀-C₁₆ alkyl.

Other suitable anionic surfactants include the alkyl sulfate surfactantswhich are water soluble salts or acids of the formula ROSO₃M wherein Rpreferably is a C₁₀-C₂₄ hydrocarbyl, preferably an alkyl or hydroxyalkylhaving a C₁₀-C₂₀ alkyl component, more preferably a C₁₂-C₁₈ alkyl orhydroxyalkyl, and M is H or a cation, e.g., an alkali metal cation (e.g.sodium, potassium, lithium), or ammonium or substituted ammonium (e.g.methyl-, dimethyl-, and trimethyl ammonium cations and quaternaryammonium cations such as tetramethyl-ammonium and dimethyl piperdiniumcations and quaternary ammonium cations derived from alkylamines such asethylamine, diethylamine, triethylamine, and mixtures thereof, and thelike). Typically, alkyl chains of C₁₂-C₁₆ are preferred for lower washtemperatures (e.g. below about 50° C.) and C₁₆-C₁₈ alkyl chains arepreferred for higher wash temperatures (e.g. above about 50° C.).

Other anionic surfactants useful for detersive purposes can also beincluded in the laundry detergent compositions of the present invention.Theses can include salts (including, for example, sodium, potassium,ammonium, and substituted ammonium salts such as mono- di- andtriethanolamine salts) of soap, C₈-C₂₂ primary or secondaryalkanesulfonates, C₈-C₂₄ olefinsulfonates, sulfonated polycarboxylicacids prepared by sulfonation of the pyrolyzed product of alkaline earthmetal citrates, e.g., as described in British patent specification No.1,082,179, C₈-C₂₄ alkylpolyglycolethersulfates (containing up to 10moles of ethylene oxide); alkyl glycerol sulfonates, fatty acyl glycerolsulfonates, fatty oleyl glycerol sulfates, alkyl phenol ethylene oxideether sulfates, paraffin sulfonates, alkyl phosphates, isethionates suchas the acyl isethionates, N-acyl taurates, alkyl succinamates andsulfosuccinates, monoesters of sulfosuccinates (especially saturated andunsaturated C₁₂-C₁₈ monoesters) and diesters of sulfosuccinates(especially saturated and unsaturated C₆-C₁₂ diesters), acylsarcosinates, sulfates of alkylpolysaccharides such as the sulfates ofalkylpolyglucoside (the nonionic nonsulfated compounds being describedbelow), branched primary alkyl sulfates, and alkyl polyethoxycarboxylates such as those of the formula RO(CH₂CH₂O)_(k)—CH₂COO—M+wherein R is a C₈-C₂₂ alkyl, k is an integer from 1 to 10, and M is asoluble salt forming cation. Resin acids and hydrogenated resin acidsare also suitable, such as rosin, hydrogenated rosin, and resin acidsand hydrogenated resin acids present in or derived from tall oil.

Alkylbenzene sulfonates are highly preferred. Especially preferred arelinear (straight-chain) alkyl benzene sulfonates (LAS) wherein the alkylgroup preferably contains from 10 to 18 carbon atoms.

Further examples are described in “Surface Active Agents and Detergents”(Vol. I and II by Schwartz, Perrry and Berch). A variety of suchsurfactants are also generally disclosed in U.S. Pat. No. 3,929,678,(Column 23, line 58 through Column 29, line 23, herein incorporated byreference).

When included in laundry detergent compositions of the presentinvention, such anionic surfactants will typically constitute from about1% to about 40%, preferably from about 3% to about 20% by weight of thecomposition.

Laundry detergent compositions of the present invention may also containcationic, ampholytic, zwitterionic, and semi-polar surfactants, as wellas the nonionic and/or anionic surfactants other than those alreadydescribed herein.

Cationic detersive surfactants suitable for use in laundry detergentcompositions of the present invention are those having one long-chainhydrocarbyl group. Examples of such cationic surfactants include theammonium surfactants such as alkyltrimethylammonium halogenides, andthose surfactants having the formula:

[R²(OR³)_(y)][R⁴(OR³)_(y)]₂R⁵N⁺X⁻

wherein R² is an alkyl or alkyl benzyl group having from about 8 toabout 18 carbon atoms in the alkyl chain, each R³ is selected form thegroup consisting of —CH₂CH₂—, —CH₂CH (CH₃)—, —CH₂CH (CH₂OH)—,—CH₂CH₂CH₂—, and mixtures thereof; each R is selected from the groupconsisting of C₁-C₄ alkyl, C₁-C₄ hydroxyalkyl, benzyl ring structuresformed by joining the two R⁴ groups, —CH₂CHOHCHOHCOR⁶CHOHCH₂OH, whereinR⁶ is any hexose or hexose polymer having a molecular weight less thanabout 1000, and hydrogen when y is not 0; R⁵ is the same as R⁴ or is analkyl chain, wherein the total number of carbon atoms or R2 plus R⁵ isnot more than about 18; each y is from 0 to about 10, and the sum of they values is from 0 to about 15; and X is any compatible anion.

Highly preferred cationic surfactants are the water soluble quaternaryammonium compounds useful in the present composition having the formula:

R₁R₂R₃R₄N⁺X⁻  (i)

wherein R₁ is C₈-C₁₆ alkyl, each of R₂, R₃ and R₄ is independently C₁-C₄alkyl, C₁-C₄ hydroxy alkyl, benzyl, and —(C₂H₄₀)_(x)H where x has avalue from 2 to 5, and X is an anion. Not more than one of R₂, R₃ or R₄should be benzyl.

The preferred alkyl chain length for R₁ is C₁₂-C₁₅, particularly wherethe alkyl group is a mixture of chain lengths derived from coconut orpalm kernel fat or is derived synthetically by olefin build up or OXOalcohols synthesis.

Preferred groups for R₂, R₃ and R₄ are methyl and hydroxyethyl groupsand the anion X may be selected from halide, methosulphate, acetate andphosphate ions.

Examples of suitable quaternary ammonium compounds of formulae (i) foruse herein are:

coconut trimethyl ammonium chloride or bromide;

coconut methyl dihydroxyethyl ammonium chloride or bromide;

decyl triethyl ammonium chloride;

decyl dimethyl hydroxyethyl ammonium chloride or bromide;

C₁₂₋₁₅ dimethyl hydroxyethyl ammonium chloride or bromide;

coconut dimethyl hydroxyethyl ammonium chloride or bromide;

myristyl trimethyl ammonium methyl sulphate;

lauryl dimethyl benzyl ammonium chloride or bromide;

lauryl dimethyl (ethenoxy)₄ ammonium chloride or bromide;

choline esters (compounds of formula (i) wherein R₁ is

alkyl and R₂, R₃ and R₄ are methyl.

di-alkyl imidazolines [compounds of formula (i)].

Other cationic surfactants useful herein are also described in U.S. Pat.No. 4,228,044 and in EP 000 224.

When included in laundry detergent compositions of the presentinvention, such cationic surfactants will typically constitute from 0.2%to about 25%, preferably from about 1% to about 8% by weight of thecomposition.

Ampholytic surfactants are also suitable for use in the laundrydetergent compositions of the present invention. These surfactants canbe broadly described as aliphatic derivatives of secondary or tertiaryamines, or aliphatic derivatives of heterocyclic secondary and tertiaryamines in which the aliphatic radical can be straight- orbranched-chain. One of the aliphatic substituents contains at leastabout 8 carbon atoms, typically from about 8 to about 18 carbon atoms,and at least one contains an anionic water-solubilizing group, e.g.carboxy, sulfonate, sulfate. See U.S. Pat. No. 3,929,678 (column 19,lines 18-35) for examples of ampholytic surfactants.

When included in laundry detergent compositions of the presentinvention, such ampholytic surfactants will typically constitute from0.2% to about 15%, preferably from about 1% to about 10% by weight ofthe composition.

Zwitterionic surfactants are also suitable for use in laundry detergentcompositions. These surfactants can be broadly described as derivativesof secondary and tertiary amines, derivatives of heterocyclic secondaryand tertiary amines, or derivatives of quaternary ammonium, quaternaryphosphonium or tertiary sulfonium compounds. See U.S. Pat. No. 3,929,678(column 19, line 38 through column 22, line 48) for examples ofzwitterionic surfactants.

When included in laundry detergent compositions of the presentinvention, such zwitterionic surfactants will typically constitute from0.2% to about 15%, preferably from about 1% to about 10% by weight ofthe composition.

Semi-polar nonionic surfactants are a special category of nonionicsurfactants which include water-soluble amine oxides containing onealkyl moiety of from about 10 to about 18 carbon atoms and 2 moietiesselected from the group consisting of alkyl groups and hydroxyalkylgroups containing from about 1 to about 3 carbon atoms; watersolublephosphine oxides containing one alkyl moiety of form about 10 to about18 carbon atoms and 2 moieties selected from the group consisting ofalkyl groups and hydroxyalkyl groups containing from about 1 to about 3carbon atoms; and water-soluble sulfoxides containing one alkyl moietyfrom about 10 to about 18 carbon atoms and a moiety selected from thegroup consisting of alkyl and hydroxyalkyl moieties of from about 1 toabout 3 carbon atoms.

Semi-polar nonionic detergent surfactants include the amine oxidesurfactants having the formula:

wherein R³ is an alkyl, hydroxyalkyl, or alkyl phenyl group or mixturesthereof containing from about 8 to about 22 carbon atoms; R⁴ is analkylene or hydroxyalkylene group containing from about 2 to about 3carbon atoms or mixtures thereof; x is from 0 to about 3: and each R⁵ isan alkyl or hydroxyalkyl group containing from about 1 to about 3 carbonatoms or a polyethylene oxide group containing from about 1 to about 3ethylene oxide groups. The R⁵ groups can be attached to each other,e.g., through an oxygen or nitrogen atom, to form a ring structure.

These amine oxide surfactants in particular include C₁₀-C₁₈ alkyldimethyl amine oxides and C₈-C₁₂ alkoxy ethyl dihydroxy ethyl amineoxides.

When included in laundry detergent compositions of the presentinvention, such semi-polar nonionic surfactants will typicallyconstitute from 0.2% to about 15%, preferably from about 1% to about 10%by weight of the composition.

The compositions according to the present invention may further comprisea builder system. Any conventional builder system is suitable for useherein including aluminosilicate materials, silicates, polycarboxylatesand fatty acids, materials such as ethylenediamine tetraacetate, metalion sequestrants such as aminopolyphosphonates, particularlyethylenediamine tetramethylene phosphonic acid and diethylene triaminepentamethylenephosphonic acid. Though less preferred for obviousenvironmental reasons, phosphate builders can also be used herein.

Suitable builders can be an inorganic ion exchange material, commonly aninorganic hydrated aluminosilicate material, more particularly ahydrated synthetic zeolite such as hydrated zeolite A, X, B, HS or MAP.

Another suitable inorganic builder material is layered silicate, e.g.SKS-6 (Hoechst). SKS-6 is a crystalline layered silicate consisting ofsodium silicate (Na₂Si₂O₅).

Suitable polycarboxylates containing one carboxy group include lacticacid, glycolic acid and ether derivatives thereof as disclosed inBelgian Patent Nos. 831,368, 821,369 and 821,370. Polycarboxylatescontaining two carboxy groups include the water-soluble salts ofsuccinic acid, malonic acid, (ethylenedioxy) diacetic acid, maleic acid,diglycollic acid, tartaric acid, tartronic acid and fumaric acid, aswell as the ether carboxylates described in German Offenle-enschrift2,446,686, and 2,446,487, U.S. Pat. No. 3,935,257 and the sulfinylcarboxylates described in Belgian Patent No. 840,623. Polycarboxylatescontaining three carboxy groups include, in particular, water-solublecitrates, aconitrates and citraconates as well as succinate derivativessuch as the carboxymethyloxysuccinates described in British Patent No.1,379,241, lactoxysuccinates described in Netherlands Application7205873, and the oxypolycarboxylate materials such as2-oxa-1,1,3-propane tricarboxylates described in British Patent No.1,387,447.

Polycarboxylates containing four carboxy groups include oxydisuccinatesdisclosed in British Patent No. 1,261,829, 1,1,2,2,-ethanetetracarboxylates, 1,1,3,3-propane tetracarboxylates containing sulfosubstituents include the sulfosuccinate derivatives disclosed in BritishPatent Nos. 1,398,421 and 1,398,422 and in U.S. Pat. No. 3,936,448, andthe sulfonated pyrolysed citrates described in British Patent No.1,082,179, while polycarboxylates containing phosphone substituents aredisclosed in British Patent No. 1,439,000.

Alicyclic and heterocyclic polycarboxylates include cyclopentane-cis,cis-cis-tetracarboxylates, cyclopentadienide pentacarboxylates,2,3,4,5-tetrahydrofuran-cis, cis, cis-tetracarboxylates,2,5-tetrahydro-furan-cis, discarboxylates,2,2,5,5,-tetrahydrofuran-tetracarboxylates,1,2,3,4,5,6-hexane-hexacarboxylates and carboxymethyl derivatives ofpolyhydric alcohols such as sorbitol, mannitol and xylitol. Aromaticpolycarboxylates include mellitic acid, pyromellitic acid and thephthalic acid derivatives disclosed in British Patent No. 1,425,343.

Of the above, the preferred polycarboxylates are hydroxy-carboxylatescontaining up to three carboxy groups per molecule, more particularlycitrates.

Preferred builder systems for use in the present compositions include amixture of a water-insoluble aluminosilicate builder such as zeolite Aor of a layered silicate (SKS-6), and a water-soluble carboxylatechelating agent such as citric acid.

A suitable chelant for inclusion in the detergent composi-ions inaccordance with the invention is ethylenediamine-N,N′-disuccinic acid(EDDS) or the alkali metal, alkaline earth metal, ammonium, orsubstituted ammonium salts thereof, or mixtures thereof. Preferred EDDScompounds are the free acid form and the sodium or magnesium saltthereof. Examples of such preferred sodium salts of EDDS include Na₂EDDSand Na₄EDDS. Examples of such preferred magnesium salts of EDDS includeMgEDDS and Mg₂EDDS. The magnesium salts are the most preferred forinclusion in compositions in accordance with the invention.

Preferred builder systems include a mixture of a water-insolublealuminosilicate builder such as zeolite A, and a water solublecarboxylate chelating agent such as citric acid.

Other builder materials that can form part of the builder system for usein granular compositions include inorganic materials such as alkalimetal carbonates, bicarbonates, silicates, and organic materials such asthe organic phosphonates, amino polyalkylene phosphonates and aminopolycarboxylates.

Other suitable water-soluble organic salts are the homo- or co-polymericacids or their salts, in which the polycarboxylic acid comprises atleast two carboxyl radicals separated form each other by not more thantwo carbon atoms.

Polymers of this type are disclosed in GB-A-1,596,756. Examples of suchsalts are polyacrylates of MW 2000-5000 and their copolymers with maleicanhydride, such copolymers having a molecular weight of from 20,000 to70,000, especially about 40,000.

Detergency builder salts are normally included in amounts of from 5% to80% by weight of the composition. Preferred levels of builder for liquiddetergents are from 5% to 30%.

The detergent compositions of the invention comprise enzymes whichprovide cleaning performance and/or fabric care benefits, as describedin the aforementioned applications.

Such enzymes include proteases, lipases, cutinases, amylases,cellulases, peroxidases and oxidases (e.g. laccases).

Proteases: Any protease suitable for use in alkaline solutions can beused. Suitable proteases include those of animal, vegetable or microbialorigin. Microbial origin is preferred. Chemically or geneticallymodified mutants are included. The protease may be a serine protease,preferably an alkaline microbial protease or a trypsin-like protease.Examples of alkaline proteases are subtilisins, especially those derivedfrom Bacillus, e.g., subtilisin Novo, subtilisin Carlsberg, subtilisin309, subtilisin 147 and subtilisin 168 (described in WO 89/06279).Examples of trypsin-like proteases are trypsin (e.g. of porcine orbovine origin) and the Fusarium protease described in WO 89/06270.

Preferred commercially available protease enzymes include those soldunder the trade names Alcalase, Savinase, Primase, Durazym, and Esperaseby Novo Nordisk A/S (Denmark), those sold under the tradename Maxatase,Maxacal, Maxapem and Properase by Gist-Brocades, those sold under thetradename Purafect and Purafect OXP by Genencor International, and thosesold under the tradename Opticlean and Optimase by Solvay Enzymes.Protease enzymes may be incorporated into the compositions in accordancewith the invention at a level of from 0.00001% to 2% of enzyme proteinby weight of the composition, preferably at a level of from 0.0001% to1% of enzyme protein by weight of the composition, more preferably at alevel of from 0.001% to 0.5% of enzyme protein by weight of thecomposition, even more preferably at a level of from 0.01% to 0.2% ofenzyme protein by weight of the composition.

Lipases: Any lipase suitable for use in alkaline solutions can be used.Suitable lipases include those of bacterial or fungal origin. Chemicallyor genetically modified mutants are included.

Examples of useful lipases include a Humicola lanuginosa lipase, e.g.,as described in EP 258 068 and EP 305 216, a Rhizomucor miehei lipase,e.g., as described in EP 238 023, a Candida lipase, such as a C.antarctica lipase, e.g., the C. antarctica lipase A or B described in EP214 761, a Pseudomonas lipase such as a P. alcaligenes and P.pseudoalcaligenes lipase, e.g., as described in EP 218 272, a P. cepacialipase, e.g., as described in EP 331 376, a P. stutzeri lipase, e.g., asdisclosed in GB 1,372,034, a P. fluorescens lipase, a Bacillus lipase,e.g., a B. subtilis lipase (Dartois et al., (1993), Biochemica etBiophysica acta 1131, 253-260), a B. stearothermophilus lipase (JP64/744992) and a B. pumilus lipase (WO 91/16422).

Furthermore, a number of cloned lipases may be useful, including thePenicillium camembertii lipase described by Yamaguchi et al., (1991),Gene 103, 61-67), the Geotricum candidum lipase (Schimada, Y. et al.,(1989), J. Biochem., 106, 383-388), and various Rhizopus lipases such asa R. delemar lipase (Hass, M. J et al., (1991), Gene 109, 117-113), a R.niveus lipase (Kugimiya et al., (1992), Biosci. Biotech. Biochem. 56,716-719) and a R. oryzae lipase.

Other types of lipolytic enzymes such as cutinases may also be useful,e.g., a cutinase derived from Pseudomonas mendocina as described in WO88/09367, or a cutinase derived from Fusarium solani pisi (e.g.described in WO 90/09446).

Especially suitable lipases are lipases such as M1 Lipase™, Luma fast™and Lipomax™ (Genencor), Lipolase™ and Lipolase Ultra™ (Novo NordiskA/S), and Lipase P “Amano” (Amano Pharmaceutical Co. Ltd.).

The lipases are normally incorporated in the detergent composition at alevel of from 0.00001% to 2% of enzyme protein by weight of thecomposition, preferably at a level of from 0.0001% to 1% of enzymeprotein by weight of the composition, more preferably at a level of from0.001% to 0.5% of enzyme protein by weight of the composition, even morepreferably at a level of from 0.01% to 0.2% of enzyme protein by weightof the composition.

Amylases: Any amylase (α and/or β) suitable for use in alkalinesolutions can be used. Suitable amylases include those of bacterial orfungal origin. Chemically or genetically modified mutants are included.Amylases include, for example, α-amylases obtained from a special strainof B. licheniformis, described in more detail in GB 1,296,839.Commercially available amylases are Duramyl™, Termamyl™, Fungamyl™ andBAN™ (available from Novo Nordisk A/S) and Rapidase™ and Maxamyl P™(available from Genencor).

The amylases are normally incorporated in the detergent composition at alevel of from 0.00001% to 2% of enzyme protein by weight of thecomposition, preferably at a level of from 0.0001% to 1% of enzymeprotein by weight of the composition, more preferably at a level of from0.001% to 0.5% of enzyme protein by weight of the composition, even morepreferably at a level of from 0.01% to 0.2% of enzyme protein by weightof the composition.

Cellulases: Any cellulase suitable for use in alkaline solutions can beused. Suitable cellulases include those of bacterial or fungal origin.Chemically or genetically modified mutants are included. Suitablecellulases are disclosed in U.S. Pat. No. 4,435,307, which disclosesfungal cellulases produced from Humicola insolens. Especially suitablecellulases are the cellulases having colour care benefits. Examples ofsuch cellulases are cellulases described in European patent applicationNo. 0 495 257.

Commercially available cellulases include Celluzyme™ produced by astrain of Humicola insolens, (Novo Nordisk A/S), and KAC-500(B)™ (KaoCorporation).

Cellulases are normally incorporated in the detergent composition at alevel of from 0.00001% to 2% of enzyme protein by weight of thecomposition, preferably at a level of from 0.0001% to 1% of enzymeprotein by weight of the composition, more preferably at a level of from0.001% to 0.5% of enzyme protein by weight of the composition, even morepreferably at a level of from 0.01% to 0.2% of enzyme protein by weightof the composition.

Peroxidases/Oxidases: Peroxidase enzymes are used in combination withhydrogen peroxide or a source thereof (e.g. a percarbonate, perborate orpersulfate). Oxidase enzymes function in combination with oxygen (e.g.oxygen present in atmospheric air). Both types of enzymes are used for“solution bleaching”, i.e. to prevent transfer of a textile dye from adyed fabric to another fabric when said fabrics are washed together in awash liquor, preferably together with an enhancing agent as described ine.g. WO 94/12621 and WO 95/01426. Suitable peroxidases/oxidases includethose of plant, bacterial or fungal origin. Chemically or geneticallymodified mutants are included.

Peroxidase and/or oxidase enzymes are normally incorporated in thedetergent composition at a level of from 0.00001% to 2% of enzymeprotein by weight of the composition, preferably at a level of from0.0001% to 1% of enzyme protein by weight of the composition, morepreferably at a level of from 0.001% to 0.5% of enzyme protein by weightof the composition, even more preferably at a level of from 0.01% to0.2% of enzyme protein by weight of the composition.

Mixtures of the above-mentioned enzymes are encompassed herein, e.g. amixture of a protease, an amylase, a lipase and/or a cellulase.

Not only the above-mentioned types of enzymes, but also any other enzymeincorporated in a detergent composition of the invention will normallybe incorporated in the detergent composition at a level of from 0.00001%to 2% of enzyme protein by weight of the composition, preferably at alevel of from 0.0001% to 1% of enzyme protein by weight of thecomposition, more preferably at a level of from 0.001% to 0.5% of enzymeprotein by weight of the composition, even more preferably at a level offrom 0.01% to 0.2% of enzyme protein by weight of the composition.

Bleaching agents: Additional optional detergent ingredients that can beincluded in detergent compositions include bleaching agents such as PB1,PB4 and percarbonate with a particle size of 400-800 microns. Thesebleaching agent components can include one or more oxygen bleachingagents and, depending upon the bleaching agent chosen, one or morebleach activators. When present oxygen bleaching compounds willtypically be present at levels of from about 1% to about 25%. Ingeneral, bleaching compounds are optional added components in non-liquidformulations, e.g. granular detergents.

The bleaching agent component for use herein can be any of the bleachingagents useful for detergent compositions including oxygen bleaches aswell as others known in the art.

The bleaching agent suitable for the present invention can be anactivated or non-activated bleaching agent.

One category of oxygen bleaching agent that can be used encompassespercarboxylic acid bleaching agents and salts thereof. Suitable examplesof this class of agents include magnesium monoperoxyphthalatehexahydrate, the magnesium salt of meta-chloro perbenzoic acid,4-nonylamino-4-oxoperoxybutyric acid and diperoxydodecanedioic acid.Such bleaching agents are disclosed in U.S. Pat. No. 4,483,781, U.S.Pat. No. 740,446, EP 0 133 354 and U.S. Pat. No. 4,412,934. Highlypreferred bleaching agents also include 6-nonylamino-6-oxoperoxycaproicacid as described in U.S. Pat. No. 4,634,551.

Another category of bleaching agents that can be used encompasses thehalogen bleaching agents. Examples of hypohalite bleaching agents, forexample, include trichloro isocyanuric acid and the sodium and potassiumdichloroisocyanurates and N-chloro and N-bromo alkane sulphonamides.Such materials are normally added at 0.5-10% by weight of the finishedproduct, preferably 1-5% by weight.

The hydrogen peroxide releasing agents can be used in combination withbleach activators such as tetra-acetylethylenediamine (TAED),nonanoyloxybenzenesulfonate (NOBS, described in U.S. Pat. No.4,412,934), 3,5-trimethyl-hexsanoloxybenzenesulfonate (ISONOBS,described in EP 120 591) or pentaacetylglucose (PAG), which areperhydrolyzed to form a peracid as the active bleaching species, leadingto improved bleaching effect. In addition, very suitable are the bleachactivators C8(6-octanamido-caproyl) oxybenzene-sulfonate,C9(6-nonanamido caproyl) oxybenzenesulfonate and C10 (6-decanamidocaproyl) oxybenzenesulfonate or mixtures thereof. Also suitableactivators are acylated citrate esters such as disclosed in EuropeanPatent Application No. 91870207.7.

Useful bleaching agents, including peroxyacids and bleaching systemscomprising bleach activators and peroxygen bleaching compounds for usein cleaning compositions according to the invention are described inapplication U.S. Ser. No. 08/136,626.

The hydrogen peroxide may also be present by adding an enzymatic system(i.e. an enzyme and a substrate therefore) which is capable ofgeneration of hydrogen peroxide at the beginning or during the washingand/or rinsing process. Such enzymatic systems are disclosed in EuropeanPatent Application EP 0 537 381.

Bleaching agents other than oxygen bleaching agents are also known inthe art and can be utilized herein. One type of non-oxygen bleachingagent of particular interest includes photoactivated bleaching agentssuch as the sulfonated zinc and/or aluminium phthalocyanines. Thesematerials can be deposited upon the substrate during the washingprocess. Upon irradiation with light, in the presence of oxygen, such asby hanging clothes out to dry in the daylight, the sulfonated zincphthalocyanine is activated and, consequently, the substrate isbleached. Preferred zinc phthalocyanine and a photoactivated bleachingprocess are described in U.S. Pat. No. 4,033,718. Typically, detergentcomposition will contain about 0.025% to about 1.25%, by weight, ofsulfonated zinc phthalocyanine.

Bleaching agents may also comprise a manganese catalyst. The manganesecatalyst may, e.g., be one of the compounds described in “Efficientmanganese catalysts for low-temperature bleaching”, Nature 369, 1994,pp. 637-639.

Suds suppressors: Another optional ingredient is a suds suppressor,exemplified by silicones, and silica-silicone mixtures. silicones cangenerally be represented by alkylated polysiloxane materials, whilesilica is normally used in finely divided forms exemplified by silicaaerogels and xerogels and hydrophobic silicas of various types. Thesesmaterials can be incorporated as particulates, in which the sudssuppressor is advantageously releasably incorporated in a water-solubleor waterdispersible, substantially non surface-active detergentimpermeable carrier. Alternatively the suds suppressor can be dissolvedor dispersed in a liquid carrier and applied by spraying on to one ormore of the other components.

A preferred silicone suds controlling agent is disclosed in U.S. Pat.No. 3,933,672. Other particularly useful suds suppressors are theself-emulsifying silicone suds suppressors, described in German PatentApplication DTOS 2,646,126. An example of such a compound is DC-544,commercially available form Dow Corning, which is a siloxane-glycolcopolymer. Especially preferred suds controlling agent are the sudssuppressor system comprising a mixture of silicone oils and2-alkyl-alkanols. Suitable 2-alkyl-alkanols are 2-butyl-octanol whichare commercially available under the trade name Isofol 12 R.

Such suds suppressor system are described in European Patent ApplicationEP 0 593 841.

Especially preferred silicone suds controlling agents are described inEuropean Patent Application No. 92201649.8. Said compositions cancomprise a silicone/silica mixture in combination with fumed nonporoussilica such as Aerosil®.

The suds suppressors described above are normally employed at levels offrom 0.001% to 2% by weight of the composition, preferably from 0.01% to1% by weight.

Other components: Other components used in detergent compositions may beemployed such as soil-suspending agents, soil-releasing agents, opticalbrighteners, abrasives, bactericides, tarnish inhibitors, coloringagents, and/or encapsulated or nonencapsulated perfumes.

Especially suitable encapsulating materials are water soluble capsuleswhich consist of a matrix of polysaccharide and polyhydroxy compoundssuch as described n GB 1,464,616.

Other suitable water soluble encapsulating materials omprise dextrinsderived from ungelatinized starch acid esters of substituteddicarboxylic acids such as described in U.S. Pat. No. 3,455,838. Theseacid-ester dextrins are, preferably, prepared from such starches as waxymaize, waxy sorghum, sago, tapioca and potato. Suitable examples of saidencapsulation materials include N-Lok manufactured by National Starch.The N-Lok encapsulating material consists of a modified maize starch andglucose. The starch is modified by adding monofunctional substitutedgroups such as octenyl succinic acid anhydride.

Antiredeposition and soil suspension agents suitable herein includecellulose derivatives such as methylcellulose, carboxymethylcelluloseand hydroxyethylcellulose, and homo- or co-polymeric polycarboxylicacids or their salts. Polymers of this type include the polyacrylatesand maleic anhydride-acrylic acid copolymers previously mentioned asbuilders, as well as copolymers of maleic anhydride with ethylene,methylvinyl ether or methacrylic acid, the maleic anhydride constitutingat least 20 mole percent of the copolymer. These materials are normallyused at levels of from 0.5% to 10% by weight, more preferably form 0.75%to 8%, most preferably from 1% to 6% by weight of the composition.

Preferred optical brighteners are anionic in character, examples ofwhich are disodium4,4′-bis-(2-diethanolamino-4-anilino-s-triazin-6-ylamino)stilbene-2:2′disulphonate, disodium4,-4′-bis-(2-morpholino-4-anilino-s-triazin-6-ylamino-stilbene-2:2′-disulphonate,disodium4,4′-bis-(2,4-dianilino-s-triazin-6-ylamino)stilbene-2:2′-disulphonate,monosodium4′,4″-bis-(2,4-dianilino-s-tri-azin-6-ylamino)stilbene-2-sulphonate,disodium4,4′-bis-(2-anilino-4-(N-methyl-N-2-hydroxyethylamino)-s-triazin-6-ylamino)stilbene-2,2′-disulphonate,di-sodium 4,4′-bis-(4-phenyl-2,1,3-triazol-2-yl)-stilbene-2,2′disulphonate, di-so-dium4,4′bis(2-anilino-4-(1-methyl-2-hydroxyethylamino)-s-triazin-6-ylamino)stilbene-2,2′disulphonate,sodium 2(stilbyl-4″-(naphtho-1′,2′:4,5)-1,2,3,-triazole-2″-sulphonateand 4,4′-bis(2-sulphostyryl)biphenyl.

Other useful polymeric materials are the polyethylene glycols,particularly those of molecular weight 1000-10000, more particularly2000 to 8000 and most preferably about 4000. These are used at levels offrom 0.20% to 5% more preferably from 0.25% to 2.5% by weight. Thesepolymers and the previously mentioned homo- or co-polymericpoly-carboxylate salts are valuable for improving whiteness maintenance,fabric ash deposition, and cleaning performance on clay, proteinaceousand oxidizable soils in the presence of transition metal impurities.

Soil release agents useful in compositions of the present invention areconventionally copolymers or terpolymers of terephthalic acid withethylene glycol and/or propylene glycol units in various arrangements.Examples of such polymers are disclosed in U.S. Pat. Nos. 4,116,885 and4,711,730 and EP 0 272 033. A particular preferred polymer in accordancewith EP 0 272 033 has the formula:

(CH₃(PEG)₄₃)_(0.75)(POH)_(0.25)[T-PO)_(2.8)(T-PEG)_(0.4)]T(POH)_(0.25)((PEG)₄₃CH₃)_(0.75)

where PEG is —(OC₂H₄)O—, PO is (OC₃H₆O) and T is (pOOC₆H₄CO).

Also very useful are modified polyesters as random copolymers ofdimethyl terephthalate, dimethyl sulfoisophthalate, ethylene glycol and1,2-propanediol, the end groups consisting primarily of sulphobenzoateand secondarily of mono esters of ethylene glycol and/or1,2-propanediol. The target is to obtain a polymer capped at both end bysulphobenzoate groups, “primarily”, in the present context most of saidcopolymers herein will be endcapped by sulphobenzoate groups. However,some copolymers will be less than fully capped, and therefore their endgroups may consist of monoester of ethylene glycol and/or1,2-propanediol, thereof consist “secondarily” of such species.

The selected polyesters herein contain about 46% by weight of dimethylterephthalic acid, about 16% by weight of 1,2-propanediol, about 10% byweight ethylene glycol, about 13% by weight of dimethyl sulfobenzoicacid and about 15% by weight of sulfoisophthalic acid, and have amolecular weight of about 3.000. The polyesters and their method ofpreparation are described in detail in EP 311 342.

Softening agents: Fabric softening agents can also be incorporated intolaundry detergent compositions in accordance with the present invention.These agents may be inorganic or organic in type. Inorganic softeningagents are exemplified by the smectite clays disclosed in GB-A-1400898and in U.S. Pat. No. 5,019,292. Organic fabric softening agents includethe water insoluble tertiary amines as disclosed in GB-A1 514 276 and EP0 011 340 and their combination with mono C₁₂-C₁₄ quaternary ammoniumsalts are disclosed in EP-B-0 026 528 and di-long-chain amides asdisclosed in EP 0 242 919. Other useful organic ingredients of fabricsoftening systems include high molecular weight polyethylene oxidematerials as disclosed in EP 0 299 575 and 0 313 146.

Levels of smectite clay are normally in the range from 5% to 15%, morepreferably from 8% to 12% by weight, with the material being added as adry mixed component to the remainder of the formulation. Organic fabricsoftening agents such as the water-insoluble tertiary amines or dilongchain amide materials are incorporated at levels of from 0.5% to 5% byweight, normally from 1% to 3% by weight whilst the high molecularweight polyethylene oxide materials and the water soluble cationicmaterials are added at levels of from 0.1% to 2%, normally from 0.15% to1.5% by weight. These materials are normally added to the spray driedportion of the composition, although in some instances it may be moreconvenient to add them as a dry mixed particulate, or spray them asmolten liquid on to other solid components of the composition.

Polymeric dye-transfer inhibiting agents: The detergent compositionsaccording to the present invention may also comprise from 0.001% to 10%,preferably from 0.01% to 2%, more preferably form 0.05% to 1% by weightof polymeric dye-transfer inhibiting agents. Said polymeric dye-transferinhibiting agents are normally incorporated into detergent compositionsin order to inhibit the transfer of dyes from colored fabrics ontofabrics washed therewith. These polymers have the ability of complexingor adsorbing the fugitive dyes washed out of dyed fabrics before thedyes have the opportunity to become attached to other articles in thewash.

Especially suitable polymeric dye-transfer inhibiting agents arepolyamine N-oxide polymers, copolymers of N-vinyl-pyrrolidone andN-vinylimidazole, polyvinyl-pyrrolidone polymers, polyvinyloxazolidonesand polyvinylimidazoles or mixtures thereof.

Aqueous liquid detergent compositions according to the present inventionmay suitably have a lower water content than many conventional aqueousliquid detergents. Thus, the water content of an aqueous liquiddetergent suitably be less than 30%, such as less than 20%, and in somecases less than 10% by weight of the detergent composition.

Compositions of the invention may for example, be formulated as handand/or machine laundry detergent compositions including laundry additivecompositions and compositions suitable for use in the pretreatment ofstained fabrics, rinse added fabric softener compositions, andcompositions for use in general household hard surface cleaningoperations and dishwashing operations.

The following exemplifies compositions for the present invention, but isin no way intended to limit or otherwise define the scope of theinvention. In the detergent compositions, the abbreviated componentidentifications have the following meanings:

LAS: Sodium linear C₁₂ alkyl benzene sulphonate

XYAS: Sodium C_(1X)-C_(1Y) alkyl sulfate

25EY: A C₁₂-C₁₅ predominantly linear primary alcohol condensed with anaverage of Y moles of ethylene oxide

XYEZS: C_(1X)-C_(1Y) sodium alkyl sulfate condensed with an average of Zmoles of ethylene oxide per mole

Two examples (compositions A and B) of heavy duty liquid fabric cleaningcompositions in accordance with the invention are as follows:

A B LAS acid form — 25.0 Citric acid 5.0 2.0 25AS acid form 8.0 — 25E2Sacid form 3.0 — 25E7 8.0 — CFAA 5 — DETPMP 1.0 1.0 Fatty acid 8 — Oleicacid — 1.0 Ethanol 4.0 6.0 1,2-Propanediol 2.0 6.0 Enzyme(s) 0.10 0.05Coco-alkyl dimethyl — 3.0 hydroxy ethyl ammonium chloride Smectite clay— 5.0 PVP 2.0 Water/Minors Up to 100% Up to 100%

The minors include the shell and core polymers.

The amount of the or each enzyme in the liquid detergent typicallycorresponds to an amount of 0.0001 to 1 mg pure enzyme protein per literof wash liquor.

Various test methods may be used to determine the storage stability ofthe concentrates of the invention. Preferably the novel concentratesgive values of less than 20%, preferably less than 15 and mostpreferably less than 10 or 5% leakage of the original enzyme activitywhen determined by such tests. In particular we describe method 1 andmethod 2 below.

Method I

The relative leak of protease from the enzyme capsules is established bymaking a storage stability series with varying concentration ofprotease. A non-protease compatible enzyme (eg a lipase) is dosed as aliquid to the liquid detergent, and the stability of the lipase ismeasured as a function of time.

If the protease capsules are dosed at 1% concentration, a proteasecontrol will be dosed with non-encapsulated enzyme at dosage whichcorrespond to a predetermined leakage, eg as follows

1% (100% leak) 0.5%  (50% leak) 0.25%  (25% leak) 0.1%  (10% leak) 0.05% (5% leak) 0.01%  (1% leak)

The resulting lipase stability of the protease control series iscompared to the capsule-containing series and the relative leakagepercent is estimated.

Method II

Reactions

The following reactions are assumed to be dominant in a liquid detergentcontaining a protease (P) and a non-protease enzyme (E):

I) P + P − P + D_(o) k₁ autoproteolysis of protease II) P − D_(P) k₂denaturation of protease III) E − D_(E) k₃ denaturation of non-proteaseIV) P + E · P + D_(E) k₄ proteolysis of non-protease

where D_(X) is deactivated enzyme X and k₁ the reaction rate constantfor reaction i.

Equations

From the reactions the following coupled differential equations for theconcentration of protease and non-protease can be derived$\begin{matrix}{\frac{\lbrack P\rbrack}{t} = {{- {k_{1}\lbrack P\rbrack}^{2}} - {k_{2}\lbrack P\rbrack}}} & (1) \\{\frac{\lbrack E\rbrack}{t} = {{- {k_{4}\lbrack P\rbrack}} - \lbrack E\rbrack - {k_{3}\lbrack E\rbrack}}} & (2)\end{matrix}$

Equation (1) can be solved by integration: $\begin{matrix}{\frac{\lbrack P\rbrack}{\lbrack P\rbrack_{0}} = \frac{k_{2}{\exp \left( {{- k_{2}}t} \right)}}{k_{2} + {k_{1}\lbrack P\rbrack}_{0} - {{k_{1}\lbrack P\rbrack}_{0}{\exp \left( {{- k_{2}}t} \right)}}}} & (3)\end{matrix}$

where [P]₀ is the amount of protease added to the detergent.

The solution to equation (2) can be found by insertion of equation (3)and integration: $\begin{matrix}{\frac{\lbrack E\rbrack}{\lbrack E\rbrack_{0}} = {{\exp {\int{\frac{k_{4}}{k_{1}}\quad \ln \quad \left( \frac{k_{2} + {k_{1}\lbrack P\rbrack}_{0} - {{k_{1}\lbrack P\rbrack}_{0}{\exp \left( {{- k_{2}}t} \right)}}}{k_{2}} \right)}}} - {k_{3}t}}} & (4)\end{matrix}$

where [E]₀ is the amount of non-protease added to the detergent.

Without protease in the detergent the non-protease activity is describedby the second part of the RNS of equation (2) with the solution:$\begin{matrix}{\frac{\lbrack E\rbrack}{\lbrack E\rbrack_{0}} - {\exp \left( {{- k_{3}}t} \right)}} & (5)\end{matrix}$

Estimation of Leaked Enzyme For Encapsulated Protease

By experiments with non-encapsulated protease and a non-protease (eg alipase) [P] and [E] are measured as a function of time and [P]₀ and [E]₀are known. The constants k₁ to k₄ are estimated using standardnon-linear parameter estimation techniques.

By experiments with encapsulated protease and a non-protease, [E] ismeasured as a function of time and [E]₀ is known. The leaked protease[P]₀ is estimated using equation (4). The percent leaked proteaseP_(leak) is then calculated by: $\begin{matrix}{P_{leak} = {100 \cdot \frac{\lbrack P\rbrack_{0}}{\lbrack P\rbrack_{dosed}}}} & (6)\end{matrix}$

where [P]_(dosed) is the dosed protease activity.

Estimation of Leaked Enzyme For Encapsulated Non-protease

By experiments with non-encapsulated non-protease k_(3L) is estimatedusing equation (5). By experiments with encapsulated non-protease thesum of encapsulated and leaked non-protease [E]_(E)+[E]_(L) are measuredas function of time. The amount of non-protease[E]_(dosed)=[E]_(E0)+[E]_(LO) added to the detergent is known and[E]_(LO) and k_(3E) are estimated using:

[E] _(L) +[E] _(E) =[E] _(LO)exp(−k _(3L))+([E]_(dosed) −[E]_(LO))exp(−k _(3E))   (7)

However, in most cases k_(3L) and k_(3E) are approximately equal andequation (7) can not be used. In this case experiments withnon-encapsulated non-protease and a protease is performed, [P] and [E]are measured as a function of time and [P]₀ and [E]₀ are known. Theconstants k₁ and k₄ are estimated using standard non-linear parameterestimation techniques.

By experiments with encapsulated non-protease and protease the amount ofleaked non-protease [E]_(LO) is estimated using equation (4) and (5):$\begin{matrix}\begin{matrix}{{\lbrack E\rbrack_{E} + \lbrack E\rbrack_{L}} = \quad {{\lbrack E\rbrack_{LO}{\exp\left( {{{- \frac{k_{4}}{k_{1}}}\quad {\ln\left( \frac{\begin{matrix}{k_{2} + {k_{1}\lbrack P\rbrack}_{0} -} \\{{k_{1}\lbrack P\rbrack}_{0}{\exp \left( {{- k_{2}}t} \right)}}\end{matrix}}{k_{2}} \right)}} - {k_{3}t}} \right)}} +}} \\{\left. \quad {\left( \lbrack E) \right\rbrack_{dosed} - \lbrack E\rbrack_{LO}} \right){\exp \left( {{- k_{3}}t} \right)}}\end{matrix} & (8)\end{matrix}$

The percent leaked non-protease E_(Leak) is then calculated by:$\begin{matrix}{{E_{leak} = {100 \cdot \frac{\lbrack E\rbrack_{LO}}{\lbrack E\rbrack_{dosed}}}}\quad} & (9)\end{matrix}$

In order to determine the release of enzyme into wash water, whichpreferably results in release of least 60% and most preferably at least80 or 90% of the original enzyme content of the capsules, it isconvenient to carry out a standard Terg-o-Tometer (T-O-M) wash test. Thefollowing test demonstrates how this is conducted on a particularproduct.

Products: Savinase capsule products dosed at an expected activity of0.0675 KNPU(S)/g

Reference: A reference curve (measured on detergent-containingunencapsulated Savinase™) with enzyme dosed at;

0 KNPU/g 0.00675 KNPU/g 0.0135 KNPU/g 0.03375 KNPU/g 0.0675 KNPU/g 0.135KNPU/g

Detergent Concentration: 2 g/l

Wash Conditions: 30° C., 10 min

Water Hardness: 15° dH

Swatches: EMPA 116, type A, 10 swatches/beaker

Procedure:

The encapsulated enzyme samples denated hereafter as I, II, III) andenzyme references are dosed into detergent concentrate (2 gdetergent/sample).

At t=0 the first detergent sample is transferred to beaker no 1 of 12 (1liter beakers).

15 sec. after the addition of detergent, the 10 swatches are put intothe wash water.

The procedure is repeated until all 12 beakers have been filled.

At=10 min and 15 sec. the swatches from beaker 1 is put into rinsewater, and this procedure is repeated for the swatches in the otherbeakers. The swatches are iron dried and the wash performance isevaluated by measuring the reflectance at 460 nm.

A calibration curve is constructed from the resulting data points forthe enzyme reference, and the apparent activity for the Savinase capsulesamples is read from the standard curve.

KNPU/g ΔR % Performance 0 0 0, 0135 3, 86 0, 027 5, 43 0, 034 6, 87 0,067 8, 62 0, 135 9, 83 I 243 8, 68 ≈95% II 252 8, 23 ≈84% III 253 8, 53≈87%

In the context of this invention proteolytic activity is expressed inKilo NOVO Protease Units (KNPU). The activity is determined relativelyto an enzyme standard (SAVINASE™) and the determination is based on thedigestion of a dimethyl casein (DMC) solution by the proteolytic enzymeat standard conditions, i.e., 50° C., pH 8.3, 9 min. reaction time, 3min. measuring time. A brochure (AF 220/1) providing further details isavailable upon request from Novo Nordisk A/S, Denmark.

EXAMPLE 1

Savinase aqueous preparation supplied by Novo Nordisk A/S havingproteolytic activity of 44 KNPU/g (777 g) is mixed with 45% polyvinylpyrrolidone K60 solution (190 g) and 32.4 g of diethylene triamine(DETA) added to this mixture.

An oil phase is prepared by mixing 221 g of 21% emulsion stabiliser with208 g of a volatile hydrocarbon solvent.

The aqueous enzyme mixture containing the DETA is added to the above oilphase and homogenised with a high shear Silverson mixer to form awater-in-oil emulsion having a mean droplet size of about 3 μm. Thetemperature of the emulsion is kept below 40° C. during this step. Afterformation of the emulsion, an extra 571 g of the volatile solvent isadded to dilute the W/O emulsion.

The resulting emulsion is placed under mechanical stirring and warmed to37° C. An oil-monomer phase is prepared by dissolving 34 g ofterephthaloyl chloride (TPC) in 966 g of the volatile solvent. Thisoil-monomer phase is added to the warm emulsion over 5 minutes toinitiate the wall forming reaction. A polyamide membrane forms aroundthe fine aqueous enzyme droplets. The reaction mixture is left stirringfor 30 minutes to complete the interfacial polymerisation.

The resultant suspension has a dispersed phase which accounted for about33% of the total weight of the suspension.

This suspension is then dehydrated by distillation and subjected to asolvent exchange process with non-ionic surfactant substantially asdescribed in Example 1 of WO 94/25560 to provide a substantially stabledispersion in non-ionic surfactant of particles having a mean size ofabout 3 μm. The suspension has approximately 40 KNPU/g proteolyticactivity.

In this process, shell formation is satisfactory, and a stablemonoparticulate dispersion is formed both initially and after thesolvent exchange and when added to detergent concentrate when thestabiliser is any of the following copolymers.

A styrene/octadecyl methacrylate/methacrylic acid copolymer in theweight ratio of 30/30/40.

Octadecyl methacrylate/methacrylic acid 66/34.

Octadecyl methacrylate/methyl methacrylate/acrylic acid 50/25/25.

Octadecyl methacrylate/methacrylic acid 64/36.

Octadecyl methacrylate/methyl methacrylate/acrylic acid/methacrylic acid40/50/5/5.

Acrylonitrile/lauryl acrylate/acrylic acid 25/35/40.

Lauryl methacrylate/styrene/acrylic acid 40/50/10.

Styrene/docosaryl acrylate/methacrylic acid 55/35/10.

Octadecyl methacrylate/vinyl acetate/methyl methacrylate/methacrylicacid 35/10/45/10.

The resultant dispersion in non-ionic surfactant can then be blendedwith other components of a conventional liquid detergent concentratethereby introducing into the detergent both the non-ionic surfactant andthe particles containing enzyme.

EXAMPLE 2

A process broadly as in Example 1 is repeated except that the aqueouscore composition is formed from 312 g of the aqueous Savinase, 77 g ofthe PVP K60 solution and 11.1 g DETA, the initial oil phase is formedfrom 105 g volatile hydrocarbon solvent and 66.1 g of a 30% solution ofstabiliser as listed in Example 1, the emulsification is conducted usinga Silverson L4R mixer at full speed for 30 minutes while cooling by icebath, 234 g of the volatile solvent is then added to the emulsion,emulsification is continued for 2 minutes, the emulsion is placed in a15° C. water bath while stirring and a solution of 11.8 g terephthaloylchloride in 390 g volatile solvent is added after heating this solutionto 45° C. The resulting emulsion is stirred at 15° C. for 1 hour.

Three liquid detergent compositions, A, B and C are prepared. A has theformulation given below. B consists of 99% of detergent A together with1% Savinase capsules introduced by adding the product of this exampleinto detergent A. Detergent C is made by mixing the same amount ofSavinase, as solution, direct into detergent A. The recipe of thedetergent and the storage stability is as follows

Detergent A:

10.3% Dodecylbenzene sulphonic acid

3.5% Lauryl alcohol polyglycolether sulphate

0.5% Oleic acid

0.5% Coconut fatty acid

6.4% Alcohol ethoxylate (7 EO)

5.1% Sodium xylenesulphonate

0.7% Ethanol

2.7% Glycerol

0.4% Sodium sulphate

2.7% Sodium carbonate

5.5% Sodium citrate, dihydrate

1.5% Citric acid, monohydrate

1.0% Sodium tetraborate

1.7% Sodium hydroxide

1.0% Lipolase™ 100L (100,000 LU/g)

Balance: Water

pH: 8.8.

Detergent B:

99% Detergent A

1% Savinase™ capsules (11.3 KNPU/g)

Detergent C:

99% Detergent A

1% Savinase™ 12.0L (12.0 KNPU/g)

The detergents were stored at 30° C. and the residual Lipolase™ activityafter 0, 3 and 7 days were analysed by Tests C and D according to theprotocols shown above.

Residual Lipolase™ activities in %:

days Detergent 0 3 7 A 100 83 67 B 100 74 55 C 100  6  0

Quick and high enzymatic recovery of Savinase™ was found when dilutingdetergent B (with capsules) 200 times in water at 25° C.

The residual Lipolase™ activity of detergent B with capsules wassignificantly better than reference detergent C with liquid Savinase™,and nearly as good as for detergent without Savinase™ present (detergentA). Upon dilution the Savinase™ is quickly released from the capsules.

EXAMPLE 3

This example shows two different ways of encapsulating the enzymewherein the enzyme is precipitated in version B before encapsulation,but not in version A.

Capsules were formed from the following ingredients, in which allamounts are specified in grams. The polymer is a copolymer of 75% byweight acrylamide and 25% acrylic acid, in the form of sodium salt ofmedium (for instance 150,000) molecular weight. Deta is diethylenetriamine. The stabiliser is copolymer of styrene, stearyl methacrylateand acrylic acid. Isopar is a trade name for a volatile hydrocarbon. TPCis terephthalyl chloride.

A B 16.1% Enzyme concentrate 63.38 45.06 Borax 0.63 0.45 29% Polymer9.96 7.08 25% Na2SO4 0.00 21.63 DETA 1.03 0.78 Stabiliser 6.10 4.34Isopar (Batch 1) 34.28 36.05 Isopar (Batch 2) 34.62 34.62  3% TPC inIsopar 43.19 32.52 Activity, KNPU 11.8 8.9

The capsules are made by dissolving the stabiliser in the first batch ofIsopar and then emulsifying the deta into this Isopar with theapplication of homogenisation for 2 minutes using a Silverson (tradename) homogeniser at full speed with cooling in an ice bath for 2minutes.

Separately, the enzyme concentrate, borax, polymer and sodium sulphate(if present), had been prepared as an aqueous enzyme phase. In processA, the solution appeared clear but in process B it appeared cloudy, as aresult of precipitation of the enzyme.

The aqueous enzyme phase is slowly added to the oil phase containingdeta, stabiliser and Isopar, the addition being conducted withemulsification using the Silverson for 10 minutes. The second batch ofIsopar is then added, with emulsification using the Silverson beingconducted for a further 2 minutes and with the water in oil emulsionbeing thermally equilibrated to 20° C. in a water bath.

Accordingly, in this process, the deta has been subjected toemulsification in the presence of a stabiliser for at least 14 minutes.

The solution of TPC is heated to 50° C. and is added quickly withvigorous stirring. The product is stirred for at least 30 minutes whilebeing held at a temperature of 20° C. A suspension of the capsules inIsopar is obtained.

If desired a non-ionic surfactant (Dobanol 25-7) can be added and theIsopar then distilled off to produce a dispersion in the surfactant.Alternatively the dispersion in Isopar can be used.

The enzymatic storage stability of encapsulated protease A and B, andliquid lipase in presence of the protease capsules has been determinedin a commercially available US liquid detergent (WISK Free Clear), wherepH was adjusted to 10.1.

Formulations:

I: 2% Savinase 4.8 L, 1% Lipolase 100 L, 97% US liquid detergent

II: 1% savinase capsules A, 1% Lipolase 100 L, 98% US liquid detergent

III: 1% Savinase capsules B, 1% Lipolase 100 L, 98% US liquid detergent

IV: 1% Lipolase 100 L, 99% US liquid detergent.

Formulations I to IV were left at 30° C. for 0, 4 and 8 days, and theresidual protease and lipase activities were measured:

Savinase stability, % residual activity:

days Formulation 0 4 8 I 100 87.2 79.1 II 100 82.9 67.6 III 100 97.491.4

The storage stability of protease capsules A, formulation II (withoutsulfate) is poorer than that of liquid protease (due to the increasedconcentration of active protease inside the capsules). Precipitating theprotease with sulfate (capsules B, formulation III) significantlyimproves the storage stability compared to both capsules A and liquidprotease.

Lipolase stability, % residual activity:

days Formulation 0 4 8 I 100 8.9 — II 100 70.2 46.1 III 100 92.6 89.1 IV100 92.3 90.2

The storage stability of lipase is significantly improved whenprecipitating the protease with sulfate. However, compared to othersystems, the storage stability of the non-precipitated composition (A)was also satisfactory.

Improved results are obtained when the polymer is replaced by the use ofsodium polyacrylate homopolymer of similar molecular weight and,especially, when the stabiliser is replaced by a copolymer of styrene,stearyl methacrylate and maleic anhydride.

What is claimed is:
 1. A liquid detergent concentrate comprising (a) anouter liquid detergent phase and (b) particles, at least 90% of whichhave a diameter below 30 μm, dispersed in the outer liquid detergentphase, wherein the particles comprise (i) a shell that is formed of acondensation polymer, which is permeable to water and low molecularweight components of the outer liquid detergent phase, and (ii) a corecomprising an enzyme, an inner liquid detergent phase and a core polymerwherein the core is surrounded by the polymer shell, and wherein theshell reduces the amount of the enzyme released from the core, the corepolymer being present in said core in an amount effective to swell saidparticle upon dilution of said liquid detergent, and thereby allowingrelease of said enzyme through said shell.
 2. A liquid detergentconcentrate according to claim 1, wherein the core polymer is containedin a phase which is separate from the inner liquid detergent phase. 3.As A liquid detergent concentrate according to claim 1, wherein thecondensation polymer is a polyamide.
 4. A liquid detergent concentrateaccording to claim 1, wherein the condensation polymer is a condensateof diethylene triamine with terephthaloyl chloride.
 5. A liquiddetergent concentrate according to claim 1, wherein the particles aremade by IFC polymerization in a water-in-oil emulsion.
 6. A liquiddetergent concentrate according to claim 5, wherein the particles havebeen made in an emulsion stabilized by an amphipathic polymericstabilizer which is soluble or swellable in the oil phase.
 7. A liquiddetergent concentrate according to claim 1, wherein the enzyme is aprotease.
 8. A liquid detergent concentrate according to claim 1,wherein the outer liquid detergent phase further comprises an enzyme. 9.A liquid detergent concentrate according to claim 1, wherein the amountof the enzyme that permeates through the shell during storage is lessthan 20% of the original amount of the enzyme in the particles.
 10. Aliquid detergent concentrate according to claim 1, wherein at least 60%of the original activity of the enzyme in the particles is released intothe wash water.
 11. A liquid detergent concentrate according to claim 1,wherein the enzyme is in precipitated form.
 12. A liquid detergentconcentrate according to claim 11, wherein the core further comprisesmonomeric electrolyte and/or polymeric electrolyte in an amountsufficient to precipitate the enzyme.
 13. A liquid detergent concentrateaccording to claim 1, wherein, upon dilution of the detergentconcentrate with water to form wash water, the particles swell and theshell stretches to provide a swollen particle having a diameter at least1.2 times the initial diameter.
 14. A liquid detergent concentrateaccording to claim 1, wherein the condensation polymer is a polyamide ora condensate of diethylene triamine with terephthaloyl chloride and theenzyme is in precipitated form.
 15. A liquid detergent concentrateaccording to claim 14, wherein the enzyme is precipitated by a monomericelectrolyte and/or polyelectrolyte.
 16. Particles comprising an aqueouscore in a shell formed of a condensation polymer by interfacialcondensation, wherein the core comprises: (a) an enzyme in precipitatedform, (b) a core polymer in an amount sufficient to swell the particleswhen introducing the particles into a wash water, and (c) a monomericand/or polymeric electrolyte to precipitate the enzyme.
 17. A process ofmaking particles according to claim 16, comprising (a) forming anaqueous composition comprising the enzyme, the core polymer and themonomeric and/or polymeric electrolyte to form the enzyme inprecipitated form, and (b) encapsulating the aqueous composition by IFCencapsulation, wherein the core polymer is present in the aqueouscomposition in an amount sufficient to swell the particles whenintroducing the particles into a wash water.